Quadratic spatial anisotropy model with singularities: comparison between exact solution and renormalisation group for crossover dependence

摘要: The authors consider a quadratic spatially anisotropic model, with (d-dperpendicular to )-dimensional defect hyperplane embedded in d space, and provide the exact solution for correlation length susceptibility arbitrary epsilon perpendicular =2-dperpendicular >0. A perturbation expansion surface interaction displays singularities therefore requires renormalisation. Renormalisation group descriptions of crossover dependence scaling amplitudes on strength are compared analytic solution. close similarities between renormalisation crossovers model phi 4 field theory suggests that results former have bearing expected faithfulness latter.