Critical limit and anisotropy in the twopoint correlation function of threedimensional O(N) models
Abstract
In threedimensional O(N) models, we investigate the lowmomentum behavior of the twopoint Green's function G(x) in the critical region of the symmetric phase. We consider physical systems whose criticality is characterized by a rotationalinvariant fixed point. In nonrotational invariant physical systems with O(N)invariant interactions, the vanishing of spaceanisotropy approaching the rotationalinvariant fixed point is described by a critical exponent ρ, which is universal and is related to the leading irrelevant operator breaking rotational invariance. At N = ∞ one finds ρ = 2. We show that, for all values of N >= 0, ρ simeq 2. NonGaussian corrections to the universal lowmomentum behavior of G(x) are evaluated, and found to be very small.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 June 1997
 DOI:
 10.1209/epl/i1997002868
 arXiv:
 arXiv:condmat/9612164
 Bibcode:
 1997EL.....38..577C
 Keywords:

 05.70.Jk;
 64.60.Fr;
 75.10.Hk;
 Critical point phenomena;
 Equilibrium properties near critical points critical exponents;
 Classical spin models;
 Condensed Matter;
 High Energy Physics  Lattice
 EPrint:
 10 pages, REVTeX