Critical exponents of the diluted Ising model between dimensions 2 and 4

Abstract

Within the massive field theoretical renormalization group approach the expressions for the beta- and gamma-functions of the anisotropic mn-vector model are obtained for general space dimension d in three-loop approximation. Resumming corresponding asymptotic series, critical exponents for the case of the weakly diluted quenched Ising model (m=1, n=0), as well as estimates for the marginal order parameter component number m_c of the weakly diluted quenched m-vector model are calculated as functions of d in the region 2 =< d <4. Conclusions concerning the effectiveness of different resummation techniques are drawn.

25 pages, latex, 1 latex picture, 5 eps-figures included