title: Bak-sneppen model near zero dimension
abstract: We consider the Bak-Sneppen model near zero dimension, where the avalanche exponent tau is close to 1 and the exponents &mgr; and sigma are close to 0. We demonstrate that tau-1=&mgr;-sigma=exp-&mgr;(-1)-gamma+ small middle dot small middle dot small middle dot in this limit, where gamma is Euler's constant. The avalanche hierarchy equation is rewritten in a form that makes it possible to find the relation between the critical exponents sigma and &mgr; with high accuracy. We obtain precise values of the critical exponents for the one and two-dimensional Bak-Sneppen model and for the one-dimensional anisotropic Bak-Sneppen model.
authors.affiliation: Departamento de Fisica and Centro de Fisica do Porto, Faculdade de Cieinsertion markncias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal and A. F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia.
authors.initials: SN
authors.lastname: Dorogovtsev
authors.initials: JF
authors.lastname: Mendes
authors.initials: YG
authors.lastname: Pogorelov