title: Endogenous versus Exogenous Origins of Diseases

abstract:
  Many illnesses are associated with an alteration of the immune system
homeostasis due to any combination of factors, including exogenous bacterial
insult, endogenous breakdown (e.g., development of a disease that results in
immuno suppression), or an exogenous hit like surgery that simultaneously
alters immune responsiveness and provides access to bacteria, or genetic
disorder. We conjecture that, as a consequence of the co-evolution of the
immune system of individuals with the ecology of pathogens, the homeostasis of
the immune system requires the influx of pathogens. This allows the immune
system to keep the ever present pathogens under control and to react and adjust
fast to bursts of infections. We construct the simplest and most general system
of rate equations which describes the dynamics of five compartments: healthy
cells, altered cells, adaptive and innate immune cells, and pathogens. We study
four regimes obtained with or without auto-immune disorder and with or without
spontaneous proliferation of infected cells. Over all regimes, we find that
seven different states are naturally described by the model: (i) strong healthy
immune system, (ii) healthy organism with evanescent immune cells, (iii)
chronic infections, (iv) strong infections, (v) cancer, (vi) critically ill
state and (vii) death. The analysis of stability conditions demonstrates that
these seven states depend on the balance between the robustness of the immune
system and the influx of pathogens.


title: Prime and composite Laurent polynomials

abstract:
  In 1922 Ritt constructed the theory of functional decompositions of
polynomials with complex coefficients. In particular, he described explicitly
indecomposable polynomial solutions of the functional equation f(p(z))=g(q(z)).
In this paper we study the equation above in the case when f,g,p,q are
holomorphic functions on compact Riemann surfaces. We also construct a
self-contained theory of functional decompositions of rational functions with
at most two poles generalizing the Ritt theory. In particular, we give new
proofs of the theorems of Ritt and of the theorem of Bilu and Tichy.


title:
Optimal encoding on discrete lattice with translational invariant
  constrains using statistical algorithms

abstract:
  In this paper will be presented methodology of encoding information in
valuations of discrete lattice with some translational invariant constrains in
asymptotically optimal way. The method is based on finding statistical
description of such valuations and changing it into statistical algorithm,
which allows to construct deterministically valuation with given statistics.
Optimal statistics allow to generate valuations with uniform distribution - we
get maximum information capacity this way. It will be shown that we can reach
the optimum for one-dimensional models using maximal entropy random walk and
that for the general case we can practically get as close to the capacity of
the model as we want (found numerically: lost 10^{-10} bit/node for Hard
Square). There will be also presented simpler alternative to arithmetic coding
method which can be used as cryptosystem and data correction method too.


title:
Large-scale instability in a sheared nonhelical turbulence: formation of
  vortical structures

abstract:
  We study a large-scale instability in a sheared nonhelical turbulence that
causes generation of large-scale vorticity. Three types of the background
large-scale flows are considered, i.e., the Couette and Poiseuille flows in a
small-scale homogeneous turbulence, and the "log-linear" velocity shear in an
inhomogeneous turbulence. It is known that laminar plane Couette flow and
antisymmetric mode of laminar plane Poiseuille flow are stable with respect to
small perturbations for any Reynolds numbers. We demonstrate that in a
small-scale turbulence under certain conditions the large-scale Couette and
Poiseuille flows are unstable due to the large-scale instability. This
instability causes formation of large-scale vortical structures stretched along
the mean sheared velocity. The growth rate of the large-scale instability for
the "log-linear" velocity shear is much larger than that for the Couette and
Poiseuille background flows. We have found a turbulent analogue of the
Tollmien-Schlichting waves in a small-scale sheared turbulence. A mechanism of
excitation of turbulent Tollmien-Schlichting waves is associated with a
combined effect of the turbulent Reynolds stress-induced generation of
perturbations of the mean vorticity and the background sheared motions. These
waves can be excited even in a plane Couette flow imposed on a small-scale
turbulence when perturbations of mean velocity depend on three spatial
coordinates. The energy of these waves is supplied by the small-scale sheared
turbulence.


title: Analysis of the convex hull of the attractor of an IFS

abstract:
  In this paper we will introduce the methodology of analysis of the convex
hull of the attractors of iterated functional systems (IFS) - compact fixed
sets of self-similarity mapping. The method is based on a function which for a
direction, gives width in that direction. We can write the self similarity
equation in terms of this function, solve and analyze them. Using this function
we can quickly check if the distance from K of a given x is smaller than a
given distance or even compute analytically convex hull area and the length of
its boundary


title: Criteria for the density property of complex manifolds

abstract:
  In this paper we suggest new effective criteria for the density property.
This enables us to give a trivial proof of the original Anders\'en-Lempert
result and to establish (almost free of charge) the algebraic density property
for all linear algebraic groups whose connected components are different from
tori or $\C_+$. As another application of this approach we tackle the question
(asked among others by F. Forstneri\v{c}) about the density of algebraic vector
fields on Euclidean space vanishing on a codimension 2 subvariety.


title:
Inhomogeneous exclusion processes with extended objects: The effect of
  defect locations

abstract:
  We study the effects of local inhomogeneities, i.e., slow sites of hopping
rate $q<1$, in a totally asymmetric simple exclusion process (TASEP) for
particles of size $\ell \geq 1$ (in units of the lattice spacing). We compare
the simulation results of $\ell =1$ and $\ell >1$ and notice that the existence
of local defects has qualitatively similar effects on the steady state. We
focus on the stationary current as well as the density profiles. If there is
only a single slow site in the system, we observe a significant dependence of
the current on the \emph{location} of the slow site for both $\ell =1$ and
$\ell >1$ cases. When two slow sites are introduced, more intriguing phenomena
emerge, e.g., dramatic decreases in the current when the two are close
together. In addition, we study the asymptotic behavior when
  $q\to 0$. We also explore the associated density profiles and compare our
findings to an earlier study using a simple mean-field theory. We then outline
the biological significance of these effects.


title:
Constraints on the Velocity and Spatial Distribution of Helium-like Ions
  in the Wind of SMC X-1 from Observations with XMM-Newton/RGS

abstract:
  We present here X-ray spectra of the HMXB SMC X-1 obtained in an observation
with the XMM observatory beginning before eclipse and ending near the end of
eclipse. With the Reflection Grating Spectrometers (RGS) on board XMM, we
observe emission lines from hydrogen-like and helium-like ions of nitrogen,
oxygen, neon, magnesium, and silicon. Though the resolution of the RGS is
sufficient to resolve the helium-like n=2->1 emission into three line
components, only one of these components, the intercombination line, is
detected in our data. The lack of flux in the forbidden lines of the
helium-like triplets is explained by pumping by ultraviolet photons from the B0
star and, from this, we set an upper limit on the distance of the emitting ions
from the star. The lack of observable flux in the resonance lines of the
helium-like triplets indicate a lack of enhancement due to resonance line
scattering and, from this, we derive a new observational constraint on the
distribution of the wind in SMC X-1 in velocity and coordinate space. We find
that the solid angle subtended by the volume containing the helium-like ions at
the neutron star multiplied by the velocity dispersion of the helium-like ions
must be less than 4pi steradians km/s. This constraint will be satisfied if the
helium-like ions are located primarily in clumps distributed throughout the
wind or in a thin layer along the surface of the B0 star.


title:
Tidal debris from high-velocity collisions as fake dark galaxies: A
  numerical model of VirgoHI21

abstract:
  High speed collisions, although current in clusters of galaxies, have long
been neglected, as they are believed to cause little damages to galaxies,
except when they are repeated, a process called harassment. In fact, they are
able to produce faint but extended gaseous tails. Such low-mass, starless,
tidal debris may become detached and appear as free floating clouds in the very
deep HI surveys that are currently being carried out. We show in this paper
that these debris possess the same apparent properties as the so-called "Dark
Galaxies", objects originally detected in HI, with no optical counterpart, and
presumably dark matter dominated. We present a numerical model of the prototype
of such Dark Galaxies - VirgoHI21 -, that is able to reproduce its main
characteristics: the one-sided tail linking it to the spiral galaxy NGC 4254,
the absence of stars, and above all the reversal of the velocity gradient along
the tail originally attributed to rotation motions caused by a massive dark
matter halo and which we find to be consistent with simple streaming motions
plus projection effects. According to our numerical simulations, this tidal
debris was expelled 750 Myr ago during a fly-by at 1100 km/s of NGC 4254 by a
massive companion which should now lie at a projected distance of about 400
kpc. A candidate for the intruder is discussed. The existence of galaxies that
have never been able to form stars had already been challenged based on
theoretical and observational grounds. Tidal collisions, in particular those
occurring at high speed, provide a much more simple explanation for the origin
of such putative Dark Galaxies.


title: Formation, Survival, and Destruction of Vortices in Accretion Disks

abstract:
  Two dimensional hydrodynamical disks are nonlinearly unstable to the
formation of vortices. Once formed, these vortices essentially survive forever.
What happens in three dimensions? We show with pseudospectral simulations that
in 3D a vortex in a short box forms and survives just as in 2D. But a vortex in
a tall box is unstable and is destroyed. In our simulation, the unstable vortex
decays into a transient turbulent-like state that transports angular momentum
outward at a nearly constant rate for hundreds of orbital times. The 3D
instability that destroys vortices is a generalization of the 2D instability
that forms them. We derive the conditions for these nonlinear instabilities to
act by calculating the coupling between linear modes, and thereby derive the
criterion for a vortex to survive in 3D as it does in 2D: the azimuthal extent
of the vortex must be larger than the scale height of the accretion disk. When
this criterion is violated, the vortex is unstable and decays. Because vortices
are longer in azimuthal than in radial extent by a factor that is inversely
proportional to their excess vorticity, a vortex with given radial extent will
only survive in a 3D disk if it is sufficiently weak. This counterintuitive
result explains why previous 3D simulations always yielded decaying vortices:
their vortices were too strong. We conclude that in protoplanetary disks weak
vortices can trap dust and serve as the nurseries of planet formation. Decaying
strong vortices might be responsible for the outwards transport of angular
momentum that is required to make accretion disks accrete.


title: Khasminskii--Whitham averaging for randomly perturbed KdV equation

abstract:
  We consider the damped-driven KdV equation $$ \dot
u-\nu{u_{xx}}+u_{xxx}-6uu_x=\sqrt\nu \eta(t,x), x\in S^1, \int u dx\equiv
\int\eta dx\equiv0, $$ where $0<\nu\le1$ and the random process $\eta$ is
smooth in $x$ and white in $t$. For any periodic function $u(x)$ let $
I=(I_1,I_2,...) $ be the vector, formed by the KdV integrals of motion,
calculated for the potential $u(x)$. We prove that if $u(t,x)$ is a solution of
the equation above, then for $0\le t\lesssim\nu^{-1}$ and $\nu\to0$ the vector
$ I(t)=(I_1(u(t,\cdot)),I_2(u(t,\cdot)),...) $ satisfies the (Whitham) averaged
equation.


title: The WKB method for conjugate points in the volumorphism group

abstract:
  In this paper, we are interested in the location of conjugate points along a
geodesic in the volumorphism group of a compact three-dimensional manifold
without boundary (the configuration space of an ideal fluid). As shown in the
author's previous work, these are typically pathological, i.e., they can occur
in clusters along a geodesic, unlike on finite-dimensional Riemannian
manifolds. (This phenomenon does not occur for the volumorphism groups of
two-dimensional manifolds, which are known to have discrete conjugate points
along any geodesic by Ebin-Misiolek-Preston.) We give an explicit algorithm for
finding them in terms of a certain ordinary differential equation, derived via
the WKB-approximation methods of Lifschitz-Hameiri and Friedlander-Vishik. We
prove that for a typical geodesic in the volumorphism group, there will be
pathological conjugate point locations filling up closed intervals; hence
typically the zeroes of Jacobi fields on the volumorphism group are dense in
intervals.


title:
Algebraic Geometry over Free Metabelian Lie Algebra I: U-Algebras and
  Universal Classes

abstract:
  This paper is the first in a series of three, the aim of which is to lay the
foundations of algebraic geometry over the free metabelian Lie algebra $F$. In
the current paper we introduce the notion of a metabelian Lie $U$-algebra and
establish connections between metabelian Lie $U$-algebras and special matrix
Lie algebras. We define the $\Delta $-localisation of a metabelian Lie
$U$-algebra $A$ and the direct module extension of the Fitting's radical of $A$
and show that these algebras lie in the universal closure of $A$.


title:
Algebraic Geometry over Free Metabelian Lie Algebra II: Finite Field
  Case

abstract:
  This paper is the second in a series of three, the aim of which is to
construct algebraic geometry over a free metabelian Lie algebra $F$. For the
universal closure of free metabelian Lie algebra of finite rank $r \ge 2$ over
a finite field $k$ we find a convenient set of axioms in the language of Lie
algebras $L$ and the language $L_{F}$ enriched by constants from $F$. We give a
description of:
  * The structure of finitely generated algebras from the universal closure of
$F_r$ in both $L$ and $L_{F_r}$
  * The structure of irreducible algebraic sets over $F_r $ and respective
coordinate algebras.
  We also prove that the universal theory of a free metabelian Lie algebra over
a finite field is decidable in both languages.


title: Semidomains and Metabelian Product of Metabelian Lie Algebras

abstract:
  This paper is the third in a series of papers, the aim of which is to
construct algebraic geometry over metabelian Lie algebras.


title:
Equilibrium sequences of non rotating and rapidly rotating crystalline
  color superconducting hybrid stars

abstract:
  The three-flavor crystalline color-superconducting (CCS) phase of quantum
chromodynamics (QCD) is a candidate phase for the ground state of cold matter
at moderate densities above the density of the deconfinement phase transition.
Apart from being a superfluid, the CCS phase has properties of a solid, such as
a lattice structure and a shear modulus, and hence the ability to sustain
multipolar deformations in gravitational equilibrium. We construct equilibrium
configurations of hybrid stars composed of nuclear matter at low, and CCS quark
matter at high, densities. Phase equilibrium between these phases is possible
only for rather stiff equations of state of nuclear matter and large couplings
in the effective Nambu--Jona-Lasinio Lagrangian describing the CCS state. We
identify a new branch of stable CCS hybrid stars within a broad range of
central densities which, depending on the details of the equations of state,
either bifurcate from the nuclear sequence of stars when the central density
exceeds that of the deconfinement phase transition or form a new family of
configurations separated from the purely nuclear sequence by an instability
region. The maximum masses of our non-rotating hybrid configurations are
consistent with the presently available astronomical bounds. The sequences of
hybrid configurations that rotate near the mass-shedding limit are found to be
more compact and thus support substantially larger spins than their same mass
nuclear counterparts.

categories: astro-ph cond-mat.supr-con hep-ph nucl-th


title:
Dielectric loss of 2D metal-insulator composite near the percolation
  threshold

abstract:
  The frequency dependence of the dielectric loss angle for a metal-insulator
composite was shown previously to be an efficient method to experimentally
determine the percolation threshold. The statistical properties of this angle
are found here to be similar to those of the critical links (supporting the
total current) near the percolation threshold close to dc and for very high
frequencies. A further discussion is provided about the way to connect this
angle to the critical links. The second aim of these studies is to connect the
frequency dependence of this angle to the proportion of the conductor or
dielectric phase in this composite.


title:
Acoustic Kappa-Density Fluctuation Waves in Suprathermal Kappa Function
  Fluids

abstract:
  We describe a new wave mode similar to the acoustic wave in which both
density and velocity fluctuate. Unlike the acoustic wave in which the
underlying distribution is Maxwellian, this new wave mode occurs when the
underlying distribution is a suprathermal kappa function and involves
fluctuations in the power law index, kappa. This wave mode always propagates
faster than the acoustic wave with an equivalent effective temperature and
becomes the acoustic wave in the Maxwellian limit as kappa goes to infinity.


title: Quasirandom groups

abstract:
  Babai and S\'os have asked whether there exists a constant c>0 such that
every finite group G has a product-free subset of size at least c|G|: that is,
a subset X that does not contain three elements x, y and z with xy=z. In this
paper we show that the answer is no. Moreover, we give a simple sufficient
condition for a group not to have any large product-free subset.


title: Fundamental Solutions for Wave Equation in de Sitter Model of Universe

abstract:
  In this article we construct the fundamental solutions for the wave equation
arising in the de Sitter model of the universe. We use the fundamental
solutions to represent solutions of the Cauchy problem and to prove the
$L^p-L^q$-decay estimates for the solutions of the equation with and without a
source term.


title: On Penrose's `before the big bang' ideas

abstract:
  We point out that algebraically special Einstein fields with twisting rays
exhibit the basic properties of conformal Universes considered recently by
Roger Penrose.


title: Galileo satellite constellation and extensions to General Relativity

abstract:
  We consider the impact of some known extensions of General Relativity in
observables that will be available with the Galileo positioning systems, and
draw conclusions as to the possibility of measuring them. We specifically
address the effects of the presence of a cosmological constant, a Yukawa-like
addition to the Newtonian potential, and the existence of an extra, constant
acceleration. We also consider the phenomenological impact of a broad class of
metric theories, which can be classified through the parameterized
Post-Newtonian formalism.


title:
The relation between the quantum games, communication complexity
  problems and Bell inequalities

abstract:
  We study the relation between the quantum games, communication complexity
problems and Bell inequalities. In particular we are interested in answering
the question whether for every element of one of these groups there is a
corresponding element in the other two. We show that there are cases where
there is no such relation. Moreover, in the communication complexity problems
for which there is no Bell inequality the advantage of the quantum strategies
over the classical ones is much higher.


title: Special types of intuitionistic fuzzy left h-ideals of hemirings

abstract:
  Characteristic, normal and completely normal intuitionistic fuzzy left
$h$-ideals of hemirings are described.


title: Axion Inflation in Type II String Theory

abstract:
  Inflationary models driven by a large number of axion fields are discussed in
the context of type IIB compactifications with N=1 supersymmetry. The inflatons
arise as the scalar modes of the R-R two-forms evaluated on vanishing
two-cycles in the compact geometry. The vanishing cycles are resolved by small
two-volumes or NS-NS B-fields which sit together with the inflatons in the same
supermultiplets. String world-sheets wrapping the vanishing cycles correct the
metric of the R-R inflatons. They can help to generate kinetic terms close to
the Planck scale and a mass hierarchy between the axions and their non-axionic
partners during inflation. At small string coupling, D-brane corrections are
subleading in the metric of the R-R inflatons. However, an axion potential can
be generated by D1 instantons or gaugino condensates on D5 branes. Models with
sufficiently large number of axions admit regions of chaotic inflation which
can stretch over the whole axion field range for potentials from gaugino
condensates. These models could allow for a possibly detectable amount of
gravitational waves with tensor to scalar ratio as high as r<0.14.


title: Fuzzy n-ary groups as a generalization of Rosenfeld's fuzzy groups

abstract:
  The notion of an $n$-ary group is a natural generalization of the notion of a
group and has many applications in different branches. In this paper, the
notion of (normal) fuzzy $n$-ary subgroup of an $n$-ary group is introduced and
some related properties are investigated. Characterizations of fuzzy $n$-ary
subgroups are given.


title:
Differentiating dark energy and modified gravity with galaxy redshift
  surveys

abstract:
  The observed cosmic acceleration today could be due to an unknown energy
component (dark energy), or a modification to general relativity (modified
gravity). If dark energy models and modified gravity models are required to
predict the same cosmic expansion history H(z), they will predict different
growth rate for cosmic large scale structure, f_g(z)=d\ln \delta/d\ln a
(\delta=(\rho_m-\bar{\rho_m})/\bar{\rho_m}), a is the cosmic scale factor). If
gravity is not modified, the measured H(z) leads to a unique prediction for
f_g(z), f_g^H(z). Comparing f_g^H(z) with the measured f_g(z) provides a
transparent and straightforward test of gravity. We show that a simple \chi^2
test provides a general figure-of-merit for our ability to distinguish between
dark energy and modified gravity given the measured H(z) and f_g(z). We study a
magnitude-limited NIR galaxy redshift survey covering >10,000 (deg)^2 and the
redshift range of 0.5<z<2. The resultant data can be divided into 7 redshift
bins, and yield the measurement of H(z) to the accuracy of 1-2% via baryon
acoustic oscillation measurements, and f_g(z) to the accuracy of a few percent
via the measurement of redshift space distortions and the bias factor which
describes how light traces mass. We find that if the H(z) data are fit by both
a DGP gravity model and an equivalent dark energy model that predict the same
expansion history, a survey area of 11,931 (deg)^2 is required to rule out the
DGP gravity model at the 99.99% confidence level. It is feasible for such a
galaxy redshift survey to be carried out by the next generation space missions
from NASA and ESA, and it will revolutionize our understanding of the universe
by differentiating between dark energy and modified gravity.


title:
alpha'^2-corrections to extremal dyonic black holes in heterotic string
  theory

abstract:
  We calculate alpha'^2-corrections to the entropy of the 5-dimensional
3-charge and the 4-dimensional 4-charge large extremal black holes using the
low energy effective action of the heterotic string theory. In the
4-dimensional case, our results are in agreement with the microscopic
statistical entropy both for the BPS and the non-BPS black holes. In the more
interesting 5-dimensional case, where the direct microscopic stringy
description is still unknown, our results for the BPS black holes are in
agreement with the results obtained from the action supplemented with
R^2-correction obtained by supersymmetric completion of the gravitational
Chern-Simons term. This agreement does not extend to the non-BPS black holes,
for which we propose a different expression for the entropy. We show that the
new expression is supported by certain alpha'^3-order calculations, and by the
arguments based on the AdS/CFT correspondence.


title: Ultra LI-ideals in lattice implication algebras and MTL-algebras

abstract:
  A mistake concerning the ultra \textit{LI}-ideal of a lattice implication
algebra is pointed out, and some new sufficient and necessary conditions for an
\textit{LI}-ideal to be an ultra \textit{LI}-ideal are given. Moreover, the
notion of an \textit{LI}-ideal is extended to MTL-algebras, the notions of a
(prime, ultra, obstinate, Boolean) \textit{LI}-ideal and an \textit{ILI}-ideal
of an MTL-algebra are introduced, some important examples are given, and the
following notions are proved to be equivalent in MTL-algebra: (1) prime proper
\textit{LI}-ideal and Boolean \textit{LI}-ideal, (2) prime proper
\textit{LI}-ideal and \textit{ILI}-ideal, (3) proper obstinate
\textit{LI}-ideal, (4) ultra \textit{LI}-ideal.


title:
Cooperative Multi-Cell Networks: Impact of Limited-Capacity Backhaul and
  Inter-Users Links

abstract:
  Cooperative technology is expected to have a great impact on the performance
of cellular or, more generally, infrastructure networks. Both multicell
processing (cooperation among base stations) and relaying (cooperation at the
user level) are currently being investigated. In this presentation, recent
results regarding the performance of multicell processing and user cooperation
under the assumption of limited-capacity interbase station and inter-user
links, respectively, are reviewed. The survey focuses on related results
derived for non-fading uplink and downlink channels of simple cellular system
models. The analytical treatment, facilitated by these simple setups, enhances
the insight into the limitations imposed by limited-capacity constraints on the
gains achievable by cooperative techniques.


title: Epigenetic Chromatin Silencing: Bistability and Front Propagation

abstract:
  The role of post-translational modification of histones in eukaryotic gene
regulation is well recognized. Epigenetic silencing of genes via heritable
chromatin modifications plays a major role in cell fate specification in higher
organisms. We formulate a coarse-grained model of chromatin silencing in yeast
and study the conditions under which the system becomes bistable, allowing for
different epigenetic states. We also study the dynamics of the boundary between
the two locally stable states of chromatin: silenced and unsilenced. The model
could be of use in guiding the discussion on chromatin silencing in general. In
the context of silencing in budding yeast, it helps us understand the phenotype
of various mutants, some of which may be non-trivial to see without the help of
a mathematical model. One such example is a mutation that reduces the rate of
background acetylation of particular histone side-chains that competes with the
deacetylation by Sir2p. The resulting negative feedback due to a Sir protein
depletion effect gives rise to interesting counter-intuitive consequences. Our
mathematical analysis brings forth the different dynamical behaviors possible
within the same molecular model and guides the formulation of more refined
hypotheses that could be addressed experimentally.


title: The genus of a curve of Fermat type

abstract:
  In this paper we begin to study curves on a weighted projective plane with
one trivial weight, ${\mathbb P}(1,m,n)$, by determining the genus of curves of
Fermat type. These are curves defined by a ``homogeneous'' polynomial analagous
to the one from Fermat's last theorem. We begin by finding local coordinates
for the standard affine cover of the plane, and then prove that the curve is
smooth. This is done by pulling the curve up to the surface's
desingularization. Then a map from the curve to ${\mathbb P^1}$ is constructed,
and it's ramification divisor is determined. We conclude by applying Hurwitz's
theorem to this map to obtain $C$'s genus.


title:
Analysis of Critical State Response in Thin Films by ac Susceptibility
  Measurements

abstract:
  Harmonic analysis of the temperature dependence of the nonlinear ac
susceptibility of Nb thin film gives excellent agreement with the
susceptibility calculated on basis of model of the hysteretic critical state in
2D disk.


title: Maturity-independent risk measures

abstract:
  The new notion of maturity-independent risk measures is introduced and
contrasted with the existing risk measurement concepts. It is shown, by means
of two examples, one set on a finite probability space and the other in a
diffusion framework, that, surprisingly, some of the widely utilized risk
measures cannot be used to build maturity-independent counterparts. We
construct a large class of maturity-independent risk measures and give
representative examples in both continuous- and discrete-time financial models.


title: Mass limits for heavy neutrinos

abstract:
  Neutrinos heavier than $M_Z/2\sim 45$ GeV are not excluded by particle
physics data. Stable neutrinos heavier than this might contribute to the cosmic
gamma ray background through annihilation in distant galaxies as well as to the
dark matter content of the universe. We calculate the evolution of the heavy
neutrino density in the universe as a function of its mass, $M_N$, and then the
subsequent gamma ray spectrum from annihilation of distant $N\bar{N}$ (from
$0<z<5$). The evolution of the heavy neutrino density in the universe is
calculated numerically. In order to obtain the enhancement due to structure
formation in the universe, we approximate the distribution of $N$ to be
proportional to that of dark matter in the GalICS model. The calculated gamma
ray spectrum is compared to the measured EGRET data. A conservative exclusion
region for the heavy neutrino mass is 100 to 200 GeV, both from EGRET data and
our re-evalutation of the Kamiokande data. The heavy neutrino contribution to
dark matter is found to be at most 15%.


title:
Upper and lower bounds on resonances for manifolds hyperbolic near
  infinity

abstract:
  For a conformally compact manifold that is hyperbolic near infinity and of
dimension $n+1$, we complete the proof of the optimal $O(r^{n+1})$ upper bound
on the resonance counting function, correcting a mistake in the existing
literature. In the case of a compactly supported perturbation of a hyperbolic
manifold, we establish a Poisson formula expressing the regularized wave trace
as a sum over scattering resonances. This leads to an $r^{n+1}$ lower bound on
the counting function for scattering poles.


title: Thermal/quantum effects and induced superstring cosmologies

abstract:
  We consider classical superstring theories on flat four dimensional
space-times, and where N=4 or N=2 supersymmetry is spontaneously broken. We
obtain the thermal and quantum corrections at the string one-loop level and
show that the back-reaction on the space-time metric induces a cosmological
evolution. We concentrate on heterotic string models obtained by
compactification on a T^6 torus and on T^6/Z_2 orbifolds. The temperature T and
the supersymmetry breaking scale M are generated via the Scherk-Schwarz
mechanism on the Euclidean time cycle and on an internal spatial cycle
respectively. The effective field theory corresponds to a no-scale
supergravity, where the corresponding no-scale modulus controls the
Susy-breaking scale. The classical flatness of this modulus is lifted by an
effective thermal potential, given by the free energy. The gravitational field
equations admit solutions where M, T and the inverse scale factor 1/a of the
universe remain proportional. In particular the ratio M/T is fixed during the
time evolution. The induced cosmology is governed by a Friedmann-Hubble
equation involving an effective radiation term ~1/a^4 and an effective
curvature term ~1/a^2, whose coefficients are functions of the complex
structure ratio M/T.


title:
Verifying the Cosmological Utility of Type Ia Supernovae: Implications
  of a Dispersion in the Ultraviolet Spectra

abstract:
  We analyze the mean rest-frame ultraviolet (UV) spectrum of Type Ia
Supernovae (SNe Ia) and its dispersion using high signal-to-noise Keck-I/LRIS-B
spectroscopy for a sample of 36 events at intermediate redshift (z=0.5)
discovered by the Canada-France-Hawaii Telescope Supernova Legacy Survey
(SNLS). We introduce a new method for removing host galaxy contamination in our
spectra, exploiting the comprehensive photometric coverage of the SNLS SNe and
their host galaxies, thereby providing the first quantitative view of the UV
spectral properties of a large sample of distant SNe Ia. Although the mean SN
Ia spectrum has not evolved significantly over the past 40% of cosmic history,
precise evolutionary constraints are limited by the absence of a comparable
sample of high quality local spectra. Within the high-redshift sample, we
discover significant UV spectral variations and exclude dust extinction as the
primary cause by examining trends with the optical SN color. Although
progenitor metallicity may drive some of these trends, the variations we see
are much larger than predicted in recent models and do not follow expected
patterns. An interesting new result is a variation seen in the wavelength of
selected UV features with phase. We also demonstrate systematic differences in
the SN Ia spectral features with SN light curve width in both the UV and the
optical. We show that these intrinsic variations could represent a statistical
limitation in the future use of high-redshift SNe Ia for precision cosmology.
We conclude that further detailed studies are needed, both locally and at
moderate redshift where the rest-frame UV can be studied precisely, in order
that future missions can confidently be planned to fully exploit SNe Ia as
cosmological probes [ABRIDGED].


title:
Constraining Muon Internal Bremsstrahlung as a Contribution to the
  MiniBooNE Low Energy Excess

abstract:
  Using a cleanly tagged data sample of $\nu_\mu$ charged current events, it is
demonstrated that the rate at which such events are mis-identified as $\nu_e$'s
is accurately simulated in the MiniBooNE $\nu_\mu \to \nu_e$ analysis. Such
mis-identification, which could arise from muon internal bremsstrahlung, is
decisively ruled out as a source of the low energy electron-like events
reported in the MiniBooNE search for $\nu_\mu \to \nu_e$ oscillations. This
refutes the conclusions of a recent paper which postulates that hard
bremsstrahlung could form a substantial background to the MiniBooNE $\nu_e$
sample.


title:
Around MOND: Lagrangians, Hubble Equations, Perturbations and External
  Field Effect

abstract:
  The MOdified Newtonian Dynamics (MOND) is presented here, as well as a theory
that can be linked to it: the theory of the Aether, a four-vector field
breaking Lorentz invariance. The form of its Lagrangian is studied, then basic
equations of the theory are rederived in a detailed way, and calculated for
different metrics, exploring the impact of non-zero spatial terms of the
Aether. A brief attempt of making the Aether Lagrangian depend on a scalar
field is presented. An analytic solving of a galaxy model with an external
field is described, which highlights the MONDian external field effect that
breaks the strong equivalence principle.


title:
Possible Enhanced Flux of Glassy Solid Helium in Cylindrical Corrugated
  Nanopores

abstract:
  By using the glassy (helium-)fluid model and boundary perturbation method, we
can obtain the velocity fields (as well as the flow rate; up to the second
order) inside the wavy-rough cylindrical nanopores which are of the same size
as those samples prepared by Kim and Chan as well as Day {\it et al.} Our
results show that the velocities measured in porous Vycor samples could be
reproduced by carefully selecting relevant parameters but those in glass
capillaries are difficult to obtain.


title: Law without Law

abstract:
  We consider a model for spacetime in which there is an ubiquitous background
Dark Energy which is the Zero Point Field. This is further modeled in terms of
a Weiner process that leads to a Random or Brownian characterization.
Nevertheless we are able to recover meaningful physics, very much in the spirit
of Wheeler's Law without Law, that is laws emerging from an underpinning of
lawlessness.


title: Simple, linear-time modular decomposition

abstract:
  Modular decomposition is fundamental for many important problems in
algorithmic graph theory including transitive orientation, the recognition of
several classes of graphs, and certain combinatorial optimization problems.
Accordingly, there has been a drive towards a practical, linear-time algorithm
for the problem. Despite considerable effort, such an algorithm has remained
elusive. The linear-time algorithms to date are impractical and of mainly
theoretical interest. In this paper we present the first simple, linear-time
algorithm to compute the modular decomposition tree of an undirected graph. The
breakthrough comes by combining the best elements of two different approaches
to the problem.


title: Strangeness and bulk freeze-out properties at RHIC

abstract:
  Identified charged kaon, pion, and proton spectra and ratios from sqrt(s_NN)
= 200 and 62.4 GeV Cu+Cu collisions are studied with a hydro-motivated
blast-wave and a statistical model framework in order to explore the
strangeness production at RHIC and characterize the bulk freeze-out properties
of the created system. The spectra are measured at mid-rapidity |y|<0.1 over
the transverse momentum range of 0.25 < p_T < 1.2 GeV/c with particle
identification derived from the ionization energy loss in the STAR Time
Projection Chamber.
  The multi-dimensional systematic study of pi(+/-), K(+/-), p and pbar
production in Cu+Cu, Au+Au, d+Au and p+p collisions is used to discuss the
energy, system size and inferred energy density dependence of freeze-out
parameters and strangeness production. The new data from Cu+Cu collisions
bridge the gap between the smaller d+Au and larger Au+Au systems, allowing a
detailed study of the onset of strangeness equilibration at RHIC.


title:
Lorentzian spacetimes with constant curvature invariants in three
  dimensions

abstract:
  In this paper we study Lorentzian spacetimes for which all polynomial scalar
invariants constructed from the Riemann tensor and its covariant derivatives
are constant (CSI spacetimes) in three dimensions. We determine all such CSI
metrics explicitly, and show that for every CSI with particular constant
invariants there is a locally homogeneous spacetime with precisely the same
constant invariants. We prove that a three-dimensional CSI spacetime is either
(i) locally homogeneous or (ii) it is locally a Kundt spacetime. Moreover, we
show that there exists a null frame in which the Riemann (Ricci) tensor and its
derivatives are of boost order zero with constant boost weight zero components
at each order. Lastly, these spacetimes can be explicitly constructed from
locally homogeneous spacetimes and vanishing scalar invariant spacetimes.


title: Aharanov-Bohm effect for the edge states of zigzag carbon nanotubes

abstract:
  Two delocalized states of metallic zigzag carbon nanotubes near the Dirac
point can be localized by the Aharanov-Bohm magnetic field around 20 Tesla. The
dependence of the localization on the length and diameter of the nanotubes
shows that the localization-delocalization transition can be observed for 2 nm
diameter tube. The mechanism of the localization is explained in terms of the
deformation-induced gauge field, which shows a topological nature of the
localization. The transition from the delocalized states to the localized
states can be observed by scanning tunneling microscopy and spectroscopy. A
similarity between the transition and the spin Hall effect is discussed.


title: The (ir)Relevance of Initial Conditions in Soft Leptogenesis

abstract:
  We explore how the initial conditions affect the final lepton asymmetry in
Soft Leptogenesis. It has been usually assumed that the initial state is a
statistical mixture of sterile sneutrinos and anti-sneutrinos with equal
abundances. We calculate the lepton asymmetry due to the most general initial
mixture. The usually assumed equal mixture produces a small, but sufficient,
lepton asymmetry which is proportional to the ratio of the supersymmetry
breaking scale over the Majorana scale. A more generic mixture, still with
equal contents of sneutrinos and anti sneutrinos, yields an unsuppressed lepton
asymmetry. Mixtures of non equal contents of sneutrinos and anti sneutrinos
result in a large lepton asymmetry too. While these results establish the
robustness of Soft Leptogenesis and other mixing based mechanisms, they also
expose their lack of predictive power.


title:
A Parameter Study of the Dust and Gas Temperature in a Field of Young
  Stars

abstract:
  We model the thermal effect of young stars on their surrounding environment
in order to understand clustered star formation. We take radiative heating of
dust, dust-gas collisional heating, cosmic-ray heating, and molecular cooling
into account. Using Dusty, a spherical continuum radiative transfer code, we
model the dust temperature distribution around young stellar objects with
various luminosities and surrounding gas and dust density distributions. We
have created a grid of dust temperature models, based on our modeling with
Dusty, which we can use to calculate the dust temperature in a field of stars
with various parameters. We then determine the gas temperature assuming energy
balance. Our models can be used to make large-scale simulations of clustered
star formation more realistic.


title: Impacts of preference and geography on epidemic spreading

abstract:
  We investigate the standard susceptible-infected-susceptible model on a
random network to study the effects of preference and geography on diseases
spreading. The network grows by introducing one random node with $m$ links on a
Euclidean space at unit time. The probability of a new node $i$ linking to a
node $j$ with degree $k_j$ at distance $d_{ij}$ from node $i$ is proportional
to $k_{j}^{A}/d_{ij}^{B}$, where $A$ and $B$ are positive constants governing
preferential attachment and the cost of the node-node distance. In the case of
A=0, we recover the usual epidemic behavior with a critical threshold below
which diseases eventually die out. Whereas for B=0, the critical behavior is
absent only in the condition A=1. While both ingredients are proposed
simultaneously, the network becomes robust to infection for larger $A$ and
smaller $B$.


title: Lie Rinehart Bialgebras for Crossed Products

abstract:
  In this paper, we study Lie Rinehart bialgebras, the algebraic generalization
of Lie bialgebroids. More precisely, we analyze the structure of Lie Rinehart
bialgebras for crossed products induced by actions of Lie algebras on K[t].


title: On the Existence of Global Bisections of Lie Groupoids

abstract:
  We show that every source connected Lie groupoid always has global bisections
through any given point. This bisection can be chosen to be the multiplication
of some exponentials as close as possible to a prescribed curve. The existence
of bisections through more than one prescribed points is also discussed. We
give some interesting applications of these results.


title:
On the photoionization of the outer electrons in noble gas endohedral
  atoms

abstract:
  We demonstrate the prominent modification of the outer shell photoionization
cross-section in noble gas (NG) endohedral atoms NG@F under the action of the
fullerene F electron shell. This shell leads to two important effects, namely
to strong enhancement of the cross-section due to fullerenes shell polarization
under the action of the incoming electromagnetic wave and to prominent
oscillation of this cross-section due to the reflection of the photoelectron
from NG by the F shell.
  All but He noble gas atoms are considered. The polarization of the fullerene
shell is expressed via the total photoabsorption cross-section of F. The
reflection of the photoelectron is taken into account in the frame of the
so-called bubble potential that is a spherical zero --thickness potential.
  It is assumed in the derivations that NG is centrally located in the
fullerene. It is assumed also, in accord with the existing experimental data,
that the fullerenes radius R is much bigger than the atomic radius and the
thickness of the fullerenes shell . These assumptions permit, as it was
demonstrated recently, to present the NG@F photoionization cross-section as a
product of the NG cross-section and two well defined calculated factors.


title: Helium stars as supernova progenitors

abstract:
  We follow the evolution of helium stars of initial mass $(2.2 - 2.5)
M_\odot$, and show that they undergo off-center carbon burning, which leaves
behind ${\mathbf \sim 0.01 M_\odot}$ of unburnt carbon in the inner part of the
core. When the carbon-oxygen core grows to Chandrasekhar mass, the amount of
left-over carbon is sufficient to ignite thermonuclear runaway. At the moment
of explosion, the star will possess an envelope of several $0.1 M_{\odot}$,
consisting of He, C, and possibly some H, perhaps producing a kind of peculiar
SN. Based on the results of Waldman and Barkat (2007) for accreting white
dwarfs, we expect to get thermonuclear runaway at a broad range of $\rho_c
\approx (1 - 6) \times 10^9 \mathrm{g cm^{-3}}$, depending on the amount of
residual carbon. We verified the feasibility of this scenario by showing that
in a close binary system with initial masses $(8.5 + 7.7) M_{\odot}$ and
initial period of 150 day the primary produces a helium remnant of $2.3
M_{\odot}$ that evolves further like the model we considered.


title:
The sectional curvature remains positive when taking quotients by
  certain nonfree actions

abstract:
  We study some cases when the sectional curvature remains positive under the
taking of quotients by certain nonfree isometric actions of Lie groups. We
consider the actions of the groups $S^1$ and $S^3$ such that the quotient space
can be endowed with a smooth structure using the fibrations
$S^3/S^1{\simeq}S^2$ and $S^7/S^3\simeq S^4$. We prove that the quotient space
carries a metric of positive sectional curvature, provided that the original
metric has positive sectional curvature on all 2-planes orthogonal to the
orbits of the action.


title: Charged fundamental particles in Wesson's IMT

abstract:
  In the framework of the Weyl-Dirac version of Wesson's Induced Matter Theory,
spherically symmetric entities filled with an electrically charged substance
are obtained in the empty 4D space-time, the brane. The substance,
characterized by mass and charge density as well by pressure, is induced by the
5D bulk. The entity is separated from the surrounding vacuum by a boundary
surface, where the metric satisfy the Schwarzschild conditions. Outside one has
the Reissner-Nordstroem metric with M=Q. These entities may be regarded as
classical (non-quantum) fundamental particles serving as constituents of quarks
and leptons.


title: Protecting entanglement via the quantum Zeno effect

abstract:
  We study the exact entanglement dynamics of two atoms in a lossy resonator.
Besides discussing the steady-state entanglement, we show that in the strong
coupling regime the system-reservoir correlations induce entanglement revivals
and oscillations and propose a strategy to fight against the deterioration of
the entanglement using the quantum Zeno effect.


title:
Inverse spectral results for Schr\"odinger operators on the unit
  interval with potentials in L^P spaces

abstract:
  We consider the Schr\"odinger operator on $[0,1]$ with potential in $L^1$. We
prove that two potentials already known on $[a,1]$ ($a\in(0,{1/2}]$) and having
their difference in $L^p$ are equal if the number of their common eigenvalues
is sufficiently large. The result here is to write down explicitly this number
in terms of $p$ (and $a$) showing the role of $p$.


title:
Optimized Design of Survivable MPLS over Optical Transport Networks.
  Optical Switching and Networking

abstract:
  In this paper we study different options for the survivability implementation
in MPLS over Optical Transport Networks in terms of network resource usage and
configuration cost. We investigate two approaches to the survivability
deployment: single layer and multilayer survivability and present various
methods for spare capacity allocation (SCA) to reroute disrupted traffic. The
comparative analysis shows the influence of the traffic granularity on the
survivability cost: for high bandwidth LSPs, close to the optical channel
capacity, the multilayer survivability outperforms the single layer one,
whereas for low bandwidth LSPs the single layer survivability is more
cost-efficient. For the multilayer survivability we demonstrate that by mapping
efficiently the spare capacity of the MPLS layer onto the resources of the
optical layer one can achieve up to 22% savings in the total configuration cost
and up to 37% in the optical layer cost. Further savings (up to 9 %) in the
wavelength use can be obtained with the integrated approach to network
configuration over the sequential one, however, at the increase in the
optimization problem complexity. These results are based on a cost model with
actual technology pricing and were obtained for networks targeted to a
nationwide coverage.


title:
Heuristic Solution to Protect Communications in WDM Networks using
  P-cycles

abstract:
  Optical WDM mesh networks are able to transport huge amount of information.
The use of such technology however poses the problem of protection against
failures such as fibre cuts. One of the principal methods for link protection
used in optical WDM networks is pre-configured protection cycle (p-cycle). The
major problem of this method of protection resides in finding the optimal set
of p-cycles which protect the network for a given distribution of working
capacity. Existing heuristics generate a large set of p-cycle candidates which
are entirely independent of the network state, and from then the good sub-set
of p-cycles which will protect the network is selected. In this paper, we
propose a new algorithm of generation of p-cycles based on the incremental
aggregation of the shortest cycles. Our generation of p-cycles depends on the
state of the network. This enables us to choose an efficient set of p-cycles
which will protect the network. The set of p-cycles that we generate is the
final set which will protect the network, in other words our heuristic does not
go through the additional step of p-cycle selection


title: Dependable k-coverage algorithms for sensor networks

abstract:
  Redundant sensing capabilities are often required in sensor network
applications due to various reasons, e.g. robustness, fault tolerance, or
increased accuracy. At the same time high sensor redundancy offers the
possibility of increasing network lifetime by scheduling sleep intervals for
some sensors and still providing continuous service with help of the remaining
active sensors. In this paper centralized and distributed algorithms are
proposed to solve the k-coverage sensing problem and maximize network lifetime.
When physically possible, the proposed robust Controlled Greedy Sleep Algorithm
provides guaranteed service independently of node and communication errors in
the network. The performance of the algorithm is illustrated and compared to
results of a random solution by simulation examples.


title: Bounding sectional curvature along a K\"ahler-Ricci flow

abstract:
  If a normalized K\"{a}hler-Ricci flow $g(t),t\in[0,\infty),$ on a compact
K\"{a}hler $n$-manifold, $n\geq 3$, of positive first Chern class satisfies
$g(t)\in 2\pi c_{1}(M)$ and has $L^{n}$ curvature operator uniformly bounded,
then the curvature operator will also uniformly bounded along the flow.
Consequently the flow will converge along a subsequence to a K\"{a}hler-Ricci
soliton.


title: An Introduction to Potential Theory in Calibrated Geometry

abstract:
  We introduce and study the notion of plurisubharmonic functions in calibrated
geometry. These functions generalize the classical plurisubharmonic functions
from complex geometry and enjoy their important properties. Moreover, they
exist in abundance whereas the corresponding pluriharmonics are generally quite
scarce. A number of the results established in complex analysis via
plurisubharmonic functions are extended to calibrated manifolds. In particular,
the notion of pseudo-convexity for a calibrated manifold (X,\phi) is introduced
and studied. Analogues of totally real submanifolds are also introduced and
used to construct enormous families of strictly \phi-convex spaces with every
topological type allowed by Morse Theory. Specific calibrations are used as
examples throughout.


title:
Duality of Positive Currents and Plurisubharmonic Functions in
  Calibrated Geometry

abstract:
  Recently the authors showed that there is a robust potential theory attached
to any calibrated manifold (X,\phi). In particular, on X there exist
\phi-plurisubharmonic functions, \phi-convex domains, \phi-convex boundaries,
etc., all inter-related and having a number of good properties. In this paper
we show that, in a strong sense, the plurisubharmonic functions are the polar
duals of the \phi-submanifolds, or more generally, the \phi-currents studied in
the original paper on calibrations. In particular, we establish an analogue of
Duval-Sibony Duality which characterizes points in the \phi-convex hull of a
compact set K in X in terms of \phi-positive Green's currents on X and Jensen
measures on K. We also characterize boundaries of \phi-currents entirely in
terms of \phi-plurisubharmonic functions. Specific calibrations are used as
examples throughout. Analogues of the Hodge Conjecture in calibrated geometry
are considered.


title:
Hysteresis Models of Dynamic Mode Atomic Force Microscopes: Analysis and
  Identification

abstract:
  A new class of models based on hysteresis functions is developed to describe
atomic force microscopes operating in dynamic mode. Such models are able to
account for dissipative phenomena in the tip-sample interaction which are
peculiar of this operation mode. The model analysis, which can be pursued using
frequency domain techniques, provides a clear insight of specific nonlinear
behaviours. Experiments show good agreement with the identified models.


title: Creation of fundamental particles in Wesson's IMT

abstract:
  Fundamental particles, regarded as the constituents of quarks and leptons,
are described classicaly in the framework of the Weyl-Dirac version of Wesson's
Induced Matter Theory. There are neutral particles and particles having charge
Q=+/-(1/3e). The particles appear on the 4D brane, our universe, and are filled
with a substance induced by the 5D bulk. This substace is taken to have mass
density, charge density, pressure and is characterized by the prematter eq. of
state P+\rho=0. The interior is separated from the surrounding vacuum by a
boundary surface where the 4D metric tensor satisfies an a'la Schwarzschild
condition. Outside of the boundary holds the Schwarzschild, or the
Reissner-Nordstroem Metric, while the particles are characterized by mass,
radius, charge.


title: Convexity properties for generalized moment maps I

abstract:
  We study generalized moment maps for a Hamiltonian action on a connected
compact $H$-twisted generalized complex manifold introduced by Lin and Tolman
and prove the convexity and connectedness properties of the generalized moment
maps for a Hamiltonian torus action.


title:
Regge behaviour of structure functions and solution of
  Dokshitzer-Gribov-Lipatov-Altarelli-Parisi Evolution equations in
  next-to-leading order at low-x

abstract:
  Deuteron and proton structure functions are derived from
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations of
singlet and non-singlet structure functions in next-to-leading order (NLO) at
low-x assuming the Regge behaviour of singlet and non-singlet structure
functions at this limit and results are compared with New Muon Collaboration
(NMC) and E665 collaboration data sets.


title:
From an Antiferromagnet to a Valence Bond Solid: Evidence for a First
  Order Phase Transition

abstract:
  Using a loop-cluster algorithm we investigate the spin 1/2 Heisenberg
antiferromagnet on a square lattice with exchange coupling $J$ and an
additional four-spin interaction of strength $Q$. We confirm the existence of a
phase transition separating antiferromagnetism at $J/Q > J_c/Q$ from a valence
bond solid (VBS) state at $J/Q < J_c/Q$. Although our Monte Carlo data are
consistent with those of previous studies, we do not confirm the existence of a
deconfined quantum critical point. Instead, using a flowgram method on lattices
as large as $80^2$, we find evidence for a weak first order phase transition.
We also present a detailed study of the antiferromagnetic phase. For $J/Q >
J_c/Q$ the staggered magnetization, the spin stiffness, and the spinwave
velocity of the antiferromagnet are determined by fitting Monte Carlo data to
analytic results from the systematic low-energy effective field theory for
magnons. Finally, we also investigate the physics of the VBS state at $J/Q <
J_c/Q$, and we show that long but finite antiferromagnetic correlations are
still present.


title: On repulsive gravitational actions

abstract:
  In particular instances and in particular regions the Einsteinian gravity
exerts a repulsive action -- and without any cosmological term. This fact could
have an interest for the explanation of the dark energy, and for the
gravitational collapses.


title: Message passing for the coloring problem: Gallager meets Alon and Kahale

abstract:
  Message passing algorithms are popular in many combinatorial optimization
problems. For example, experimental results show that {\em survey propagation}
(a certain message passing algorithm) is effective in finding proper
$k$-colorings of random graphs in the near-threshold regime. In 1962 Gallager
introduced the concept of Low Density Parity Check (LDPC) codes, and suggested
a simple decoding algorithm based on message passing. In 1994 Alon and Kahale
exhibited a coloring algorithm and proved its usefulness for finding a
$k$-coloring of graphs drawn from a certain planted-solution distribution over
$k$-colorable graphs. In this work we show an interpretation of Alon and
Kahale's coloring algorithm in light of Gallager's decoding algorithm, thus
showing a connection between the two problems - coloring and decoding. This
also provides a rigorous evidence for the usefulness of the message passing
paradigm for the graph coloring problem. Our techniques can be applied to
several other combinatorial optimization problems and networking-related
issues.


title: Supersymmetry, quark confinement and the harmonic oscillator

abstract:
  We study some quantum systems described by noncanonical commutation relations
formally expressed as [q,p]=ihbar(I + chi H), where H is the associated
(harmonic oscillator-like) Hamiltonian of the system, and chi is a Hermitian
(constant) operator, i.e. [H,chi]=0 . In passing, we also consider a simple
(chi=0 canonical) model, in the framework of a relativistic Klein-Gordon-like
wave equation.


title:
Interactions of Heavy Hadrons using Regge Phenomenology and the Quark
  Gluon String Model

abstract:
  The search for stable heavy exotic hadrons is a promising way to observe new
physics processes at collider experiments. The discovery potential for such
particles can be enhanced or suppressed by their interactions with detector
material. This paper describes a model for the interactions in matter of stable
hadrons containing an exotic quark of charges $\pm {1/3}e$ or $\pm {2/3}e$
using Regge phenomenology and the Quark Gluon String Model. The influence of
such interactions on searches at the LHC is also discussed.


title:
Geometric phases in semiconductor spin qubits: Manipulations and
  decoherence

abstract:
  We describe the effect of geometric phases induced by either classical or
quantum electric fields acting on single electron spins in quantum dots in the
presence of spin-orbit coupling. On one hand, applied electric fields can be
used to control the geometric phases, which allows performing quantum coherent
spin manipulations without using high-frequency magnetic fields. On the other
hand, fluctuating fields induce random geometric phases that lead to spin
relaxation and dephasing, thus limiting the use of such spins as qubits. We
estimate the decay rates due to piezoelectric phonons and conduction electrons
in the circuit, both representing dominant electric noise sources with
characteristically differing power spectra.


title:
Complementarity of perturbations driving insulator-to-metal transition
  in a charge ordered manganite

abstract:
  Modulation of charge carrier dynamics and hence electrical conductivity of
solids by photoexcitation has been a rich field of research with numerous
applications. Similarly, electric and magnetic field assisted enhancement of
conductivity are of fundamental importance and technological use. Hole doped
manganites of the type (A$_{1-x}$B$_{x})$MnO$_{3}$, where A and B are rare and
alkaline earth metals respectively have the distinction of showing all three
effects. Here we establish the complementarity of the electric, magnetic and
photon fields in driving an insulator-metal transition in epitaxial thin films
of La$_{0.175}$Pr$_{0.45}$Ca$_{0.375}$MnO$_{3}$ whose electrical ground state
is insulating. Both pulsed and CW lasers cause a giant photon flux dependent
enhancement of conductivity. It is further observed that electric and magnetic
fields trigger the persistent enhancement of conductivity whose magnitude can
be accentuated by application of these fields in parallel.


title: Energy-momentum tensor in thermal strong-field QED with unstable vacuum

abstract:
  The mean value of the one-loop energy-momentum tensor in thermal QED with
electric-like background that creates particles from vacuum is calculated. The
problem differes essentially from calculations of effective actions (similar to
that of Heisenberg--Euler) in backgrounds that do not violate the stability of
vacuum. The role of a constant electric background in the violation of both the
stability of vacuum and the thermal character of particle distribution is
investigated. Restrictions on the electric field and its duration under which
one can neglect the back-reaction of created particles are established.


title:
New mechanism of generation of large-scale magnetic field in a sheared
  turbulent plasma

abstract:
  A review of recent studies on a new mechanism of generation of large-scale
magnetic field in a sheared turbulent plasma is presented. This mechanism is
associated with the shear-current effect which is related to the W x J-term in
the mean electromotive force. This effect causes the generation of the
large-scale magnetic field even in a nonrotating and nonhelical homogeneous
sheared turbulent convection whereby the alpha effect vanishes. It is found
that turbulent convection promotes the shear-current dynamo instability, i.e.,
the heat flux causes positive contribution to the shear-current effect.
However, there is no dynamo action due to the shear-current effect for small
hydrodynamic and magnetic Reynolds numbers even in a turbulent convection, if
the spatial scaling for the turbulent correlation time is k^{-2}, where k is
the small-scale wave number. We discuss here also the nonlinear mean-field
dynamo due to the shear-current effect and take into account the transport of
magnetic helicity as a dynamical nonlinearity. The magnetic helicity flux
strongly affects the magnetic field dynamics in the nonlinear stage of the
dynamo action. When the magnetic helicity flux is not small, the saturated
level of the mean magnetic field is of the order of the equipartition field
determined by the turbulent kinetic energy. The obtained results are important
for elucidation of origin of the large-scale magnetic fields in astrophysical
and cosmic sheared turbulent plasma.


title: Magnetic Reversal Time in Open Long Range Systems

abstract:
  Topological phase space disconnection has been recently found to be a general
phenomenon in isolated anisotropic spin systems. It sets a general framework to
understand the emergence of ferromagnetism in finite magnetic systems starting
from microscopic models without phenomenological on-site barriers. Here we
study its relevance for finite systems with long range interacting potential in
contact with a thermal bath. We show that, even in this case, the induced
magnetic reversal time is exponentially large in the number of spins, thus
determining {\it stable} (to any experimental observation time) ferromagnetic
behavior. Moreover, the explicit temperature dependence of the magnetic
reversal time obtained from the microcanonical results, is found to be in good
agreement with numerical simulations. Also, a simple and suggestive expression,
indicating the Topological Energy Threshold at which the disconnection occurs,
as a real energy barrier for many body systems, is obtained analytically for
low temperature.


title: Improved Hardy-Sobolev inequalities

abstract:
  The main result includes features of a Hardy-type inequality and an
inequality of either Sobolev or Gagliardo-Nirenberg type. It is inspired by the
method of proof of a recent improved Sobolev inequality derived by M. Ledoux
which brings out the connection between Sobolev embeddings and heat kernel
bounds. Here Ledoux's technique is applied to the operator $L:= {\bf{x}} \cdot
\nabla$ and the analysis requires the determination of the operator semigroup
$\{e^{-tL^{*}L}\}_{t>0}$ and its properties.


title: An Analytic Proof of the Matrix Spectral Factorization Theorem

abstract:
  An analytic proof is proposed of Wiener's theorem on factorization of
positive definite matrix-functions.


title:
Multiplicity Fluctuations in Limited Segments of Momentum Space in
  Statistical Models

abstract:
  Multiplicity fluctuations in limited segments of momentum space are
calculated for a classical pion gas within the statistical model. Results for
the grand canonical, canonical, and micro-canonical ensemble are obtained,
compared and discussed. We demonstrate that even in the large volume limit
correlations between macroscopic subsystems due to energy and momentum
conservation persist. Based on the micro-canonical formulation we make
qualitative predictions for the rapidity and transverse momentum dependence of
multiplicity fluctuations. The resulting effects are of similar magnitude as
the predicted enhancement due to a phase transition from a quark-gluon plasma
to a hadron gas phase, or due to the critical point of strongly interacting
matter, and qualitatively agree with recently published preliminary
multiplicity fluctuation data of the NA49 SPS experiment.


title: Rotational symmetry breaking in baby Skyrme models

abstract:
  We consider multisolitons with charges 1 =< B =< 5 in the baby Skyrme model
for the one-parametric family of potentials U=\mu^2 (1-\phi_3)^s with 0<s =< 4.
This class of potentials is a generalization of the `old' (s=1) and
`holomorphic' (s=4) baby Skyrme models. We find that for charge one, stable
solutions exist for every value of s and they are rotationally-symmetric. For
higher charges, stable solutions exist only below s \approx 2. In the
charge-two sector the stable solutions are always rotationally-symmetric and
ring-like. For charge three and above, rotational symmetry is exhibited only in
the small s region; above a certain critical value of s, this symmetry is
broken and a strong repulsion between the constituent one-Skyrmions becomes
apparent. We also compute the spatial energy distributions of these solutions.


title:
A classical picture of the role of vacancies and interstitials in
  Helium-4

abstract:
  Motivated by experimental hints for supersolidity in Helium-4, we perform
Monte Carlo simulations of vacancies and interstitials in a classical two-and
three-dimensional Lennard-Jones solid. We confirm a strong binding energy of
vacancies which is of the order of Lennard-Jones attraction. This is
reminiscent of what has been found for vacancies in Quantum Monte Carlo
simulations. In addition, we find a strong attraction and large binding energy
of interstitials in two-dimensional simulations. This is mainly due to the
formation of a pair of dislocations by clustering interstitials, in which
minimizes the elastic deformation energy. We interpret the results in light of
the properties of Helium-4.


title: Solutions of Nuclear Pairing

abstract:
  We give the exact solution of orbit dependent nuclear pairing problem between
two non-degenerate energy levels using the Bethe ansatz technique. Our solution
reduces to previously solved cases in the appropriate limits including
Richardson's treatment of reduced pairing in terms of rational Gaudin algebra
operators.


title: Bottom Baryon Decays in Non-relativistic Quark Model

abstract:
  The reactions $\Sigma_b^* \to \Lambda_b \pi$, $\Sigma_b \to \Lambda_b \pi$,
and $\Xi_b^* \to \Xi_b \pi$ are studied in the $^3P_0$ non-relativistic quark
model with all the model parameters fixed in the sector of light quarks. The
theoretical predictions for the decay widths $\Gamma_{\Sigma_b^* \to \Lambda_b
\pi}$ and $\Gamma_{\Sigma_b \to \Lambda_b \pi}$ are consistent with the
experimental data of the CDF Collaboration. Using as an input the recent mass
of $\Xi_b$ and the theoretical predictions mass of $\Xi_b^{*}$, a narrow decay
width about 1 MeV is predicted for the bottom baryon $\Xi_b^*$. The work
suggests that the $^3P_0$ quark dynamics is of independence of environments
where heavy quarks may or may not be a component of baryons.


title: Change of strength of vortex pinning in YBCO due to BaZrO_3 inclusions

abstract:
  We probe the short-range pinning properties with the application of microwave
currents at very high driving frequencies (47.7 GHz) on
YBa$_2$Cu$_3$O$_{7-\delta}$ films with and without sub-micrometer BaZrO$_3$
inclusions. We explore the temperature and field ranges 60 K$<T<T_c$ and
0$<\mu_0H<$0.8 T, with the field applied along the c-axis. The magnetic field
induces a much smaller increase of the microwave resistivity, $\Delta
\rho_1(H)+\mathrm{i}\Delta \rho_2(H)$, in YBa$_2$Cu$_3$O$_{7-\delta}$/BaZrO$_3$
with respect to pure YBa$_2$Cu$_3$O$_{7-\delta}$. $\Delta \rho_1(H)$ is
slightly superlinear in pure YBa$_2$Cu$_3$O$_{7-\delta}$ (suggesting a possible
contribution of thermal activation), but linear or sublinear in
YBa$_2$Cu$_3$O$_{7-\delta}$/BaZrO$_3$ (suggesting a possible suppression of
thermal activation as a consequence of BaZrO$_3$ inclusions). These features
persist up to close to $T_c$. We discuss our data in terms of the ratio
$r=\Delta X_s'(H)/\Delta R_s'(H)$ in the framework of the models for the
microwave surface impedance in the mixed state. Large $r$ are found in
YBa$_2$Cu$_3$O$_{7-\delta}$/BaZrO$_3$, with little field dependence. By
contrast, smaller values and stronger field dependences are found in pure
YBa$_2$Cu$_3$O$_{7-\delta}$. We discuss the different field dependence of the
pinning constant.


title:
Crystallographic modelling of protein loops and their heterogeneity with
  Rappertk

abstract:
  Background. All-atom crystallographic refinement of proteins is a laborious
manually driven procedure, as a result of which, alternative and multiconformer
interpretations are not routinely investigated.
  Results. We describe efficient loop sampling procedures in Rappertk and
demonstrate that single loops in proteins can be automatically and accurately
modelled with few positional restraints. Loops constructed with a composite
CNS/Rappertk protocol consistently have better Rfree than those with CNS alone.
This approach is extended to a more realistic scenario where there are often
large positional uncertainties in loops along with small imperfections in the
secondary structural framework. Both ensemble and collection methods are used
to estimate the structural heterogeneity of loop regions.
  Conclusion. Apart from benchmarking Rappertk for the all-atom protein
refinement task, this work also demonstrates its utility in both aspects of
loop modelling - building a single conformer and estimating structural
heterogeneity the loops can exhibit.


title: Pinning down the New Minimal Supersymmetric GUT

abstract:
  We show that generic $ {\bf{10\oplus 120\oplus {\bar {126}}}}$ fits of
fermion masses and mixings, using real superpotential couplings but with
complex `Higgs fractions' leading to complex yukawa couplings in the effective
MSSM, \emph{overdetermine}(by one extra constraint) the superpotential
parameters of the New Minimal Supersymmetric SO(10) GUT\cite{nmsgut}. Therefore
fits should properly be done by generating the 24 generic fit parameters from
the 23 parameters of the NMSGUT superpotential, given $\tan\beta$ as input.
Each numerical fit then \emph{fully specifies} the parameters of the NMSGUT. An
analysis of all its implications, modulo only the residual uncertainty of
supersymmetry breaking parameters, is now feasible. Thus the NMSGUT offers the
possibility of a confrontation between the scale of gauge unification and the
fit to fermion masses due to their extractable common dependence on the NMSGUT
parameters. If and when `smoking gun' discoveries of Supersymmetry and Proton
decay occur they will find the NMSGUT fully vulnerable to falsification.


title: Search for Supersymmetry in Di-Photon Final States at sqrt{s} = 1.96 TeV

abstract:
  We report results of a search for supersymmetry (SUSY) with gauge-mediated
symmetry breaking in di-photon events collected by the D0 experiment at the
Fermilab Tevatron Collider in 2002--2006. In 1.1 fb$^{-1}$ of data, we find no
significant excess beyond the background expected from the standard model and
set the most stringent lower limits to date for a standard benchmark model on
the lightest neutralino and chargino masses of 125 GeV and 229 GeV,
respectively, at 95% confidence.


title: First Eigenvalues of Geometric Operators under the Ricci Flow

abstract:
  In this paper, we prove that the first eigenvalues of $-\Delta + cR$ ($c\geq
\frac14$) is nondecreasing under the Ricci flow. We also prove the monotonicity
under the normalized flow for the case $c=1/4$, and $r\le 0$.


title: RNA sampling and crystallographic refinement using Rappertk

abstract:
  Background. Dramatic increases in RNA structural data have made it possible
to recognize its conformational preferences much better than a decade ago. This
has created an opportunity to use discrete restraint-based conformational
sampling for modelling RNA and automating its crystallographic refinement.
Results. All-atom sampling of entire RNA chains, termini and loops is achieved
using the Richardson RNA backbone rotamer library and an unbiased distribution
for glycosidic dihedral angle. Sampling behaviour of Rappertk on a diverse
dataset of RNA chains under varying spatial restraints is benchmarked. The
iterative composite crystallographic refinement protocol developed here is
demonstrated to outperform CNS-only refinement on parts of tRNA(Asp) structure.
Conclusion. This work opens exciting possibilities for further work in RNA
modelling and crystallography.


title: A note on pairs of metrics in a two-dimensional linear vector space

abstract:
  Pairs of metrics in a two-dimensional linear vector space are considered, one
of which is a Minkowski type metric. Their simultaneous diagonalizability is
studied and canonical presentations for them are suggested.


title:
Geometric phase gate on an optical transition for ion trap quantum
  computation

abstract:
  We propose a geometric phase gate of two ion qubits that are encoded in two
levels linked by an optical dipole-forbidden transition. Compared to hyperfine
geometric phase gates mediated by electric dipole transitions, the gate has
many interesting properties, such as very low spontaneous emission rates,
applicability to magnetic field insensitive states, and use of a co-propagating
laser beam geometry. We estimate that current technology allows for
infidelities of around 10$^{-4}$.


title:
Nonlinear elasticity of composite networks of stiff biopolymers with
  flexible linkers

abstract:
  Motivated by recent experiments showing nonlinear elasticity of in vitro
networks of the biopolymer actin cross-linked with filamin, we present an
effective medium theory of flexibly cross-linked stiff polymer networks. We
model such networks by randomly oriented elastic rods connected by flexible
connectors to a surrounding elastic continuum, which self-consistently
represents the behavior of the rest of the network. This model yields a
crossover from a linear elastic regime to a highly nonlinear elastic regime
that stiffens in a way quantitatively consistent with experiment.


title:
The fractional stochastic heat equation on the circle: Time regularity
  and potential theory

abstract:
  We consider a system of $d$ linear stochastic heat equations driven by an
additive infinite-dimensional fractional Brownian noise on the unit circle
$S^1$. We obtain sharp results on the H\"older continuity in time of the paths
of the solution $u=\{u(t, x)\}_{t \in \mathbb{R}_+, x \in S^1}$. We then
establish upper and lower bounds on hitting probabilities of $u$, in terms of
respectively Hausdorff measure and Newtonian capacity.


title: Strategy for early SUSY searches at ATLAS

abstract:
  The CERN Large Hadron Collider (LHC) is scheduled to commence operation in
2008 and inclusive searches for supersymmetry (SUSY) will be one of our primary
tasks in the first days of LHC operation. It is certain that the final state of
multijets + missing transverse energy will provide a superior performance in
SUSY searches. Strategies to understand the instrumental background and to
understand the Standard Model (SM) background are still under development and
are urgent issues for the coming data. We describe the strategy for early SUSY
searches at the ATLAS experiment using the fist data corresponding to an
integrated luminosity up to 1fb^-1, which comprises much progress in the
data-driven technique for the SM background estimations.


abstract:
  We describe the Seiberg-Witten map for the 4D noncommutative BF theory
(NCBF). We establish the existence of a map taking the abelian NCBF into its
commutative version, in agreement with the hypothesis that such maps are
available for any noncommutative theory with Schwarz type topological sectors.


title:
On the Behavior of the Distributed Coordination Function of IEEE 802.11
  with Multirate Capability under General Transmission Conditions

abstract:
  The aim of this paper is threefold. First, it presents a multi-dimensional
Markovian state transition model characterizing the behavior of the IEEE 802.11
protocol at the Medium Access Control layer which accounts for packet
transmission failures due to channel errors modeling both saturated and
non-saturated traffic conditions. Second, it provides a throughput analysis of
the IEEE 802.11 protocol at the data link layer in both saturated and
non-saturated traffic conditions taking into account the impact of both the
physical propagation channel and multirate transmission in Rayleigh fading
environment. The general traffic model assumed is M/M/1/K. Finally, it shows
that the behavior of the throughput in non-saturated traffic conditions is a
linear combination of two system parameters; the payload size and the packet
rates, $\lambda^{(s)}$, of each contending station. The validity interval of
the proposed model is also derived.
  Simulation results closely match the theoretical derivations, confirming the
effectiveness of the proposed models.


title: The solution of a memorable problem by a special artifice of calculation

abstract:
  E731 in the Enestrom index. Originally published as "Solutio problematis ob
singularia calculi artificia memorabilis", Memoires de l'academie des sciences
de St-Petersbourg 2 (1810), 3-9.
  For $z$ the distance from the origin, and $v$ a given function of $z$, Euler
wants to find a curve $s$ such that the integral of $z$ over $s$ is a maximum
or a minimum. He starts with the Euler-Lagrange equation, and does a lot of
manipulations with polar coordinates.


title:
Non-archimedean equidistribution on elliptic curves with global
  applications

abstract:
  Let $E$ be an elliptic curve over an algebraically closed, complete,
non-archimedean field $K$, and let ${\mathsf E}$ denote the Berkovich analytic
space associated to $E/K$. We study the $\mu$-equidistribution of finite
subsets of $E(K)$, where $\mu$ is a certain canonical unit Borel measure on
${\mathsf E}$. Our main result is an inequality bounding the error term when
testing against a certain class of continuous functions on ${\mathsf E}$. We
then give two applications to elliptic curves over global function fields: we
prove a function field analogue of the Szpiro-Ullmo-Zhang equidistribution
theorem for small points, and a function field analogue of a result of
Baker-Ih-Rumely on the finiteness of $S$-integral torsion points. Both
applications are given in explicit quantitative form.


title: The problem of gauge invariance and the functional Schroedinger approach

abstract:
  Quantum field theory is assumed to be gauge invariant. However it is well
known that when certain quantities, such as the vacuum current, are calculated
the results are not gauge invariant. The non-gauge invariant terms have to be
removed in order to obtain a physically correct result. It has been shown in
Ref. [3] and [4] that this problem may be due to a mathematical inconsistency
in the canonical formulation of QFT. In this article we will review this
previous work and then examine an alternative formulation of QFT called the
functional Schroedinger approach. It will be shown that this approach produces
different results then the canonical formulation. In particular it will be
shown that in the functional Schroedinger approach the vacuum current is gauge
invariant.


title:
The t copula with Multiple Parameters of Degrees of Freedom: Bivariate
  Characteristics and Application to Risk Management

abstract:
  The t copula is often used in risk management as it allows for modelling tail
dependence between risks and it is simple to simulate and calibrate. However,
the use of a standard t copula is often criticized due to its restriction of
having a single parameter for the degrees of freedom (dof) that may limit its
capability to model the tail dependence structure in a multivariate case. To
overcome this problem, grouped t copula was proposed recently, where risks are
grouped a priori in such a way that each group has a standard t copula with its
specific dof parameter. In this paper we propose the use of a grouped t copula,
where each group consists of one risk factor only, so that a priori grouping is
not required. The copula characteristics in the bivariate case are studied. We
explain simulation and calibration procedures, including a simulation study on
finite sample properties of the maximum likelihood estimators and Kendall's tau
approximation. This new copula can be significantly different from the standard
t copula in terms of risk measures such as tail dependence, value at risk and
expected shortfall.
  Keywords: grouped t copula, tail dependence, risk management.


title: A Kruskal-Katona Type Theorem for Graphs

abstract:
  A bound on consecutive clique numbers of graphs is established. This bound is
evaluated and shown to often be much better than the bound of the
Kruskal-Katona theorem. A bound on non-consecutive clique numbers is also
proven.


title:
On a New Type of Information Processing for Efficient Management of
  Complex Systems

abstract:
  It is a challenge to manage complex systems efficiently without confronting
NP-hard problems. To address the situation we suggest to use self-organization
processes of prime integer relations for information processing.
Self-organization processes of prime integer relations define correlation
structures of a complex system and can be equivalently represented by
transformations of two-dimensional geometrical patterns determining the
dynamics of the system and revealing its structural complexity. Computational
experiments raise the possibility of an optimality condition of complex systems
presenting the structural complexity of a system as a key to its optimization.
  From this perspective the optimization of a system could be all about the
control of the structural complexity of the system to make it consistent with
the structural complexity of the problem. The experiments also indicate that
the performance of a complex system may behave as a concave function of the
structural complexity. Therefore, once the structural complexity could be
controlled as a single entity, the optimization of a complex system would be
potentially reduced to a one-dimensional concave optimization irrespective of
the number of variables involved its description. This might open a way to a
new type of information processing for efficient management of complex systems.


title: d+id'-wave Superconducting States in Graphene

abstract:
  We show that effective superconducting orders generally emerge at low energy
in the superconducting state of graphene with conventionally defined pairing
symmetry .
  We study such a particular interesting example, the $d_{x^2-y^2}+id'_{xy}$
spin singlet pairing superconducting state in graphene, which can be generated
by electronic correlation as well as induced through a proximity effect with a
d-wave superconductor. We find that effectively the d-wave state is a state
with mixed s-wave and exotic $p+ip$-wave pairing orders at low energy. This
remarkable property leads to distinctive superconducting gap functions and
novel behavior of the Andreev conductance spectra.


title:
Including nonlocality in exchange-correlation kernel from time-dependent
  current density functional theory: Application to the stopping power of
  electron liquids

abstract:
  We develop a scheme for building the scalar exchange-correlation (xc) kernel
of time-dependent density functional theory (TDDFT) from the tensorial kernel
of time-dependent {\em current} density functional theory (TDCDFT) and the
Kohn-Sham current density response function. Resorting to the local
approximation to the kernel of TDCDFT results in a nonlocal approximation to
the kernel of TDDFT, which is free of the contradictions that plague the
standard local density approximation (LDA) to TDDFT. As an application of this
general scheme, we calculate the dynamical xc contribution to the stopping
power of electron liquids for slow ions to find that our results are in
considerably better agreement with experiment than those obtained using TDDFT
in the conventional LDA.


title: A note on a curious formula for Euler's constant

abstract:
  In this short note we will use the residue theorem to establish a formula for
Euler's constant. In particular, we offer a slightly generalized version of an
interesting infinite series due to Flajolet, Gourdon, and Dumas.


title: Quasisymmetric functions and Kazhdan-Lusztig polynomials

abstract:
  We associate a quasisymmetric function to any Bruhat interval in a general
Coxeter group. This association can be seen to be a morphism of Hopf algebras
to the subalgebra of all peak functions, leading to an extension of the
cd-index of convex polytopes. We show how the Kazhdan-Lusztig polynomial of the
Bruhat interval can be expressed in terms of this complete cd-index and
otherwise explicit combinatorially defined polynomials. In particular, we
obtain the simplest closed formula for the Kazhdan-Lusztig polynomials that
holds in complete generality.


title: Overview of progress in neutrino scattering measurements

abstract:
  Recent progress in neutrino scattering experiments with few GeV neutrino
beams is reviewed, focusing on new experimental input since the beginning of
the NuInt workshop series in 2001. Progress in neutrino quasi-elastic
scattering, resonance production, coherent pion production, scattering in the
transition region between the resonance and deep inelastic regimes, and nuclear
effects in neutrino-nucleus scattering, is discussed.


title:
Associahedra, Cyclohedra and a Topological solution to the
  A_{\infty}--Deligne conjecture

abstract:
  We give a topological solution to the $\Ainf$ Deligne conjecture using
associahedra and cyclohedra. For this we construct three CW complexes whose
cells are indexed by products of polytopes. Giving new explicit realizations of
the polytopes in terms of different types of trees, we are able to show that
the CW complexes are cell models for the little discs. The cellular chains of
one complex in particular, which is built out of associahedra and cyclohedra,
naturally acts on the Hochschild cochains of an $\Ainf$ algebra yielding an
explicit, topological and minimal solution to the $\Ainf$ Deligne conjecture.
  Along the way we obtain new results about the cyclohedra, such as a new
decompositions into products of cubes and simplices, which can be used to
realize them via a new iterated blow--up construction.


title:
Gromov-Witten invariants of blow-ups along submanifolds with convex
  normal bundles

abstract:
  Given a submanifold Z inside X, let Y be the blow-up of X along Z. When the
normal bundle of Z in X is convex with a minor assumption, we prove that
genus-zero GW-invariants of Y with cohomology insertions from X, are identical
to GW-invariants of X. Under the same hypothesis, a vanishing theorem is also
proved. An example to which these two theorems apply is when the normal bundle
is generated by global sections. These two main theorems do not hold for
arbitrary blow-ups, and counter-examples are included.


title: Primordial Mass Segregation in Starburst Stellar Clusters

abstract:
  We present a model to explain the mass segregation and shallow mass functions
observed in the central parts of dense and young starburst stellar clusters.
The model assumes that the initial pre-stellar cores mass function resulting
from the turbulent fragmentation of the proto-cluster cloud is significantly
altered by the cores coalescence before they collapse to form stars. With
appropriate, yet realistic parameters, this model based on the competition
between cores coalescence and collapse reproduces the mass spectra of the well
studied Arches cluster. Namely, the slopes at the intermediate and high mass
ends are reproduced, as well as the peculiar bump observed at 6 M_sol. This
coalescence-collapse process occurs on short timescale of the order of one
fourth the free fall time of the proto-cluster cloud (i.e., a few 10^{4}
years), suggesting that mass segregation in Arches and similar clusters is
primordial. The best fitting model implies the total mass of the Arches cluster
is 1.45 10^{5} M_sol, which is slightly higher than the often quoted, but
completeness affected, observational value of a few 10^{4} M_sol. The derived
star formation efficiency is ~30 percent which implies that the Arches cluster
is likely to be gravitationally bound.


title: An Overview of the SPACE Mission Proposal

abstract:
  SPACE (SPectroscopic All-sky Cosmic Explorer) is a class-M mission proposed
to ESA for the Cosmic Vision 2015-2025 call and recently promoted to the next
assessment study phase. SPACE will produce the first all-sky spectroscopic
survey of the Universe, taking spectra of more than 500 million galaxies over a
wide range of redshifts. SPACE will operate in slit mode (MEMS) at R~400
between 0.8 and 1.8micron down to AB~23, providing redshifts to an accuracy of
Delta z~0.001, regardless on the presence of bright emission lines, together
with the most relevant physical and evolutionary properties. The catalog of
spectroscopic redshift will allow to place the ultimate constraints on the
Baryon Acoustic Oscillations and the nature of Dark Energy. By obtaining the
first 3-D all-sky map of the Universe at z~2 and beyond, SPACE will trace the
growth rate of cosmic structures, the large scale structure of luminous baryons
and its cosmic evolution. Besides the all-sky survey, SPACE will carry out a
deep extragalactic survey over an area of ~10 sq. deg., enabling a most
powerful supernova search program, and a galactic plane survey in integral
field mode. Approximately 30% of the time will be open. Due to its versatility,
SPACE is a ``self-sufficient'' observatory which can attack and solve the most
compelling questions on the nature of the Dark Energy without complementary
data from the Earth or space. Its unique wide-field capabilities in the near-IR
make SPACE the ideal complement to JWST, ALMA, and the future 25-50 m
telescopes.


title: Spontaneous Supersymmetry Breaking by Large-N Matrices

abstract:
  Motivated by supersymmetry breaking in matrix model formulations of
superstrings, we present some concrete models, in which the supersymmetry is
preserved for any finite $N$, but gets broken at infinite $N$, where $N$ is the
rank of matrix variables. The models are defined as supersymmetric field
theories coupled to some matrix models, and in the induced action obtained
after integrating out the matrices, supersymmetry is spontaneously broken only
when $N$ is infinity. In our models, the large value of $N$ gives a natural
explanation for the origin of small parameters appearing in the field theories
which trigger the supersymmetry breaking. In particular, in the case of the
O'Raifeartaigh model coupled to a certain supersymmetric matrix model, a
nonsupersymmetric metastable vacuum appears near the origin of the field space,
which is far from the position of the supersymmetric vacuum. We estimate its
lifetime as a function of $N$.


title: Centrality measures and thermodynamic formalism for complex networks

abstract:
  In the study of small and large networks it is customary to perform a simple
random walk, where the random walker jumps from one node to one of its
neighbours with uniform probability. The properties of this random walk are
intimately related to the combinatorial properties of the network. In this
paper we propose to use the Ruelle-Bowens random walk instead, whose
probability transitions are chosen in order to maximise the entropy rate of the
walk on an unweighted graph. If the graph is weighted, then a free energy is
optimised instead of entropy rate.
  Specifically, we introduce a centrality measure for large networks, which is
the stationary distribution attained by the the Ruelle-Bowens random walk; we
name it Entropy Rank. We introduce a more general version, able to deal with
disconnected networks, under the name of Free Energy Rank. We compare the
properties of those centrality measures with the classic PageRank and HITS on
both toy and real-life examples, in particular their robustness to small
modifications of the network. It is observed that our centrality measures have
a better discriminating power than PageRank, being able to distinguish clearly
pages that PageRank holds for almost equally interesting, and is more sensitive
to the medium-scale details of the graph.


title:
Diffusion in the Continuous-Imaginary-Time Quantum World-Line Monte
  Carlo Simulations with Extended Ensembles

abstract:
  The dynamics of samples in the continuous-imaginary-time quantum world-line
Monte Carlo simulations with extended ensembles are investigated. In the case
of a conventional flat ensemble on the one-dimensional quantum S=1 bi-quadratic
model, the asymmetric behavior of Monte Carlo samples appears in the diffusion
process in the space of the number of vertices. We prove that a local
diffusivity is asymptotically proportional to the number of vertices, and we
demonstrate the asymmetric behavior in the flat ensemble case. On the basis of
the asymptotic form, we propose the weight of an optimal ensemble as
$1/\sqrt{n}$, where $n$ denotes the number of vertices in a sample. It is shown
that the asymmetric behavior completely vanishes in the case of the proposed
ensemble on the one-dimensional quantum S=1 bi-quadratic model.


title: Distributed source coding in dense sensor networks

abstract:
  We study the problem of the reconstruction of a Gaussian field defined in
[0,1] using N sensors deployed at regular intervals. The goal is to quantify
the total data rate required for the reconstruction of the field with a given
mean square distortion. We consider a class of two-stage mechanisms which a)
send information to allow the reconstruction of the sensor's samples within
sufficient accuracy, and then b) use these reconstructions to estimate the
entire field. To implement the first stage, the heavy correlation between the
sensor samples suggests the use of distributed coding schemes to reduce the
total rate. We demonstrate the existence of a distributed block coding scheme
that achieves, for a given fidelity criterion for the reconstruction of the
field, a total information rate that is bounded by a constant, independent of
the number $N$ of sensors. The constant in general depends on the
autocorrelation function of the field and the desired distortion criterion for
the sensor samples. We then describe a scheme which can be implemented using
only scalar quantizers at the sensors, without any use of distributed source
coding, and which also achieves a total information rate that is a constant,
independent of the number of sensors. While this scheme operates at a rate that
is greater than the rate achievable through distributed coding and entails
greater delay in reconstruction, its simplicity makes it attractive for
implementation in sensor networks.