8,901 research outputs found
Phase diagram of random lattice gases in the annealed limit
An analysis of the random lattice gas in the annealed limit is presented. The
statistical mechanics of disordered lattice systems is briefly reviewed. For
the case of the lattice gas with an arbitrary uniform interaction potential and
random short-range interactions the annealed limit is discussed in detail. By
identifying and extracting an entropy of mixing term, a correct physical
expression for the pressure is explicitly given. As an application, the
one-dimensional lattice gas with uniform long-range interactions and random
short-range interactions satisfying a bimodal annealed probability distribution
is discussed. The model is exactly solved and is shown to present interesting
behavior in the presence of competition between interactions, such as the
presence of three phase transitions at constant temperature and the occurrence
of triple and quadruple points.Comment: Final version to be published in the Journal of Chemical Physic
Axioms for the coincidence index of maps between manifolds of the same dimension
We study the coincidence theory of maps between two manifolds of the same
dimension from an axiomatic viewpoint. First we look at coincidences of maps
between manifolds where one of the maps is orientation true, and give a set of
axioms such that characterizes the local index (which is an integer valued
function). Then we consider coincidence theory for arbitrary pairs of maps
between two manifolds. Similarly we provide a set of axioms which characterize
the local index, which in this case is a function with values in . We also show in each setting that the group of values for the index
(either or ) is determined by the axioms.
Finally, for the general case of coincidence theory for arbitrary pairs of
maps between two manifolds we provide a set of axioms which charaterize the
local Reidemeister trace which is an element of an abelian group which depends
on the pair of functions. These results extend known results for coincidences
between orientable differentiable manifolds.Comment: 29 page
The improved nuclear parton distributions
In this paper we propose an improvement of the EKS nuclear parton
distributions for the small x region of high energy processes, where the
perturbative high parton density effects cannot be disregarded. We analyze the
behavior of the ratios and and verify that at small x
they are strongly modified when compared to the EKS predictions. The
implications of our results for the heavy ion collisions in RHIC and LHC are
discussed.Comment: 16 pages, 2 figure
Nonlinear Boundary Value Problems via Minimization on Orlicz-Sobolev Spaces
We develop arguments on convexity and minimization of energy functionals on
Orlicz-Sobolev spaces to investigate existence of solution to the equation
\displaystyle -\mbox{div} (\phi(|\nabla u|) \nabla u) = f(x,u) + h \mbox{in}
\Omega under Dirichlet boundary conditions, where
is a bounded smooth domain, is a
suitable continuous function and
satisfies the Carath\'eodory conditions, while is a measure.Comment: 14 page
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