The renormalized zero-momentum four-point coupling g(r) of O(N)-invariant scalar field theories in d dimensions is studied by applying the 1/N expansion and strong-coupling analysis. The O(1/N) correction to the beta-function and to the fixed point value g(r)* are explicitly computed. Strong-coupling series for lattice non-linear sigma models are analyzed near criticality in d = 2 and d = 3 for several values of N and the corresponding values of g(r)* are extracted. Large-N and strong-coupling results are compared with each other, finding a good general agreement. For small N the strong-coupling analysis in 2d gives the best determination of g(r)* to date (for N = 2, 3 it is comparable with the best Monte Carlo estimates); in 3d it is consistent with available phi(4) field theory results.
Four-point renormalized coupling constant in O(N) models
ROSSI, PAOLO;VICARI, ETTORE
1996-01-01
Abstract
The renormalized zero-momentum four-point coupling g(r) of O(N)-invariant scalar field theories in d dimensions is studied by applying the 1/N expansion and strong-coupling analysis. The O(1/N) correction to the beta-function and to the fixed point value g(r)* are explicitly computed. Strong-coupling series for lattice non-linear sigma models are analyzed near criticality in d = 2 and d = 3 for several values of N and the corresponding values of g(r)* are extracted. Large-N and strong-coupling results are compared with each other, finding a good general agreement. For small N the strong-coupling analysis in 2d gives the best determination of g(r)* to date (for N = 2, 3 it is comparable with the best Monte Carlo estimates); in 3d it is consistent with available phi(4) field theory results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
