
%0 Journal Article
%A Hamer, C. J. 
%T Finite-Size Scaling and Effective Lagrangian Theory
%J Australian Journal of Physics
%D 1997/12/20
%V 50
%N 6
%P 1051-1060
%K 
%R https://doi.org/10.1071/P97001
%U https://www.publish.csiro.au/paper/P97001 
%X A brief review is given of the &#8216;effective Lagrangian&#8217; approach of Leutwyler, Hasenfratz and others, which describes the behaviour at low energies or temperatures, or large distances, in lattice systems which undergo a first-order transition involving spontaneous breakdown of a continuous symmetry. Universal predictions can be given, based on a continuum field theory of the massless Goldstone bosons generated by the breakdown of the symmetry, which control the behaviour in these regimes. In particular, the finite-size scaling behaviour can be predicted, in a way very similar to the predictions of conformal invariance for a two-dimensional system at a critical point. Conversely, measurements of the finite-size scaling behaviour can give estimates of the parameters of the Goldstone bosons. These points are illustrated using data for the O(2) Heisenberg spin model in (2+1) dimensions, and the XXZ antiferromagnet on a square lattice. 
