Modification of the topological expansion of the O(3) sigma model
Abstract
We show that the oneinstanton sector modulispace divergence of the O(3) sigma model leads to an unacceptable dependence of Green functions on the arbitrary way that the field is split into a quantum fluctuation about a classical background. In particular the rotational symmetry of the model is spoilt. Since the divergence is associated with the degeneration of field configurations to those of the zeroinstanton sector this arbitrariness may be cancelled by modifying the zeroinstanton functional integral. We explicitly construct this modification.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1996
 DOI:
 10.1016/05503213(96)886986
 Bibcode:
 1996NuPhB.462..141C