Two interacting diffusing particles on low-dimensional discrete structures

In this paper we study the motion of two particles diffusing on low-dimensional discrete structures in presence of a hard-core repulsive interaction. We show that the problem can be mapped in two decoupled problems of single particles diffusing on different graphs by a transformation we call 'diffusion graph transform'. This technique is applied to study two specific cases: the narrow comb and the ladder lattice. We focus on the determination of the long time probabilities for the contact between particles and their reciprocal crossing. We also obtain the mean square dispersion of the particles in the case of the narrow comb lattice. The case of a sticking potential and of 'vicious' particles are discussed.Comment: 9 pages, 6 postscript figures, to appear in 'Journal of Physics A',-January 200

Otomicosis por Aspergillus niger

El 15% al 20% de las otitis externas son atribuidas a una etiología fúngica, aunque en los últimos años esto parece ir en aumento debido a la utilización de antibióticos de amplio espectro, alteraciones de la inmunidad y uso de corticosteroides, entre otros factores.Fil: Cattana, Maria Emilia. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, M, S.. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Rojas, Florencia Dinorah. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Sosa, M. A.. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Giusiano, Gustavo Emilio. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Topology Induced Spatial Bose-Einstein Condensation for Bosons on Star-Shaped Optical Networks

New coherent states may be induced by pertinently engineering the topology of a network. As an example, we consider the properties of non-interacting bosons on a star network, which may be realized with a dilute atomic gas in a star-shaped deep optical lattice. The ground state is localized around the star center and it is macroscopically occupied below the Bose-Einstein condensation temperature T_c. We show that T_c depends only on the number of the star arms and on the Josephson energy of the bosonic Josephson junctions and that the non-condensate fraction is simply given by the reduced temperature T/T_c.Comment: 20 Pages, 5 Figure

Topology-Induced Critical Current Enhancement in Josephson Networks

We investigate the properties of Josephson junction networks with inhomogeneous architecture. The networks are shaped as "quare comb" planar lattices on which Josephson junctions link superconducting islands arranged in the plane to generate the pertinent topology. Compared to the behavior of reference linear arrays, the temperature dependencies of the Josephson currents of the branches of the network exhibit relevant differences. The observed phenomena evidence new and surprising behavior of superconducting Josephson arrays as well as remarkable similarities with bosonic junction arrays.Comment: improved figures (added magnetic pattern and single junction switching) some changes in the text and in the titl