Publication details for Professor Emeritus Paul MansfieldCostambeys, R. & Mansfield, P. (1996). Modification of the topological expansion of the O(3) sigma model. Nuclear Physics B 462(1): 141-166.
- Publication type: Journal Article
- ISSN/ISBN: 0550-3213
- DOI: 10.1016/0550-3213(96)88698-6
- Keywords: Sigma model, Instantons, Renormalisation, Moduli space divergence, BRST invariance.
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Author(s) from Durham
We show that the one-instanton sector moduli-space 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 zero-instanton sector this arbitrariness may be cancelled by modifying the zero-instanton functional integral. We explicitly construct this modification.