3,944 research outputs found
The valuation of clean spread options: linking electricity, emissions and fuels
The purpose of the paper is to present a new pricing method for clean spread options, and to illustrate its main features on a set of numerical examples produced by a dedicated computer code. The novelty of the approach is embedded in the use of a structural model as opposed to reduced-form models which fail to capture properly the fundamental dependencies between the economic factors entering the production process
Finite size effects and the order of a phase transition in fragmenting nuclear systems
We discuss the implications of finite size effects on the determination of
the order of a phase transition which may occur in infinite systems. We
introduce a specific model to which we apply different tests. They are aimed to
characterise the smoothed transition observed in a finite system. We show that
the microcanonical ensemble may be a useful framework for the determination of
the nature of such transitions.Comment: LateX, 5 pages, 5 figures; Fig. 1 change
Harmonic crossover exponents in O(n) models with the pseudo-epsilon expansion approach
We determine the crossover exponents associated with the traceless tensorial
quadratic field, the third- and fourth-harmonic operators for O(n) vector
models by re-analyzing the existing six-loop fixed dimension series with
pseudo-epsilon expansion. Within this approach we obtain the most accurate
theoretical estimates that are in optimum agreement with other theoretical and
experimental results.Comment: 12 pages, 1 figure. Final version accepted for publicatio
Stabilization of internal space in noncommutative multidimensional cosmology
We study the cosmological aspects of a noncommutative, multidimensional
universe where the matter source is assumed to be a scalar field which does not
commute with the internal scale factor. We show that such noncommutativity
results in the internal dimensions being stabilizedComment: 8 pages, 1 figure, to appear in IJMP
Viscosity solutions of systems of PDEs with interconnected obstacles and Multi modes switching problems
This paper deals with existence and uniqueness, in viscosity sense, of a
solution for a system of m variational partial differential inequalities with
inter-connected obstacles. A particular case of this system is the
deterministic version of the Verification Theorem of the Markovian optimal
m-states switching problem. The switching cost functions are arbitrary. This
problem is connected with the valuation of a power plant in the energy market.
The main tool is the notion of systems of reflected BSDEs with oblique
reflection.Comment: 36 page
Anderson Localization, Non-linearity and Stable Genetic Diversity
In many models of genotypic evolution, the vector of genotype populations
satisfies a system of linear ordinary differential equations. This system of
equations models a competition between differential replication rates (fitness)
and mutation. Mutation operates as a generalized diffusion process on genotype
space. In the large time asymptotics, the replication term tends to produce a
single dominant quasispecies, unless the mutation rate is too high, in which
case the populations of different genotypes becomes de-localized. We introduce
a more macroscopic picture of genotypic evolution wherein a random replication
term in the linear model displays features analogous to Anderson localization.
When coupled with non-linearities that limit the population of any given
genotype, we obtain a model whose large time asymptotics display stable
genotypic diversityComment: 25 pages, 8 Figure
The background from single electromagnetic subcascades for a stereo system of air Cherenkov telescopes
The MAGIC experiment, a very large Imaging Air Cherenkov Telescope (IACT)
with sensitivity to low energy (E < 100 GeV) VHE gamma rays, has been operated
since 2004. It has been found that the gamma/hadron separation in IACTs becomes
much more difficult below 100 GeV [Albert et al 2008] A system of two large
telescopes may eventually be triggered by hadronic events containing Cherenkov
light from only one electromagnetic subcascade or two gamma subcascades, which
are products of the single pi^0 decay. This is a possible reason for the
deterioration of the experiment's sensitivity below 100 GeV. In this paper a
system of two MAGIC telescopes working in stereoscopic mode is studied using
Monte Carlo simulations. The detected images have similar shapes to that of
primary gamma-rays and they have small sizes (mainly below 400 photoelectrons
(p.e.)) which correspond to an energy of primary gamma-rays below 100 GeV. The
background from single or two electromagnetic subcascdes is concentrated at
energies below 200 GeV. Finally the number of background events is compared to
the number of VHE gamma-ray excess events from the Crab Nebula. The
investigated background survives simple cuts for sizes below 250 p.e. and thus
the experiment's sensitivity deteriorates at lower energies.Comment: 15 pages, 7 figures, published in Journ.of Phys.
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