Renormalization group flow and fixed point of the lattice topological charge in the 2D O(3) {sigma} model
- Dipartimento di Fisica dellUniversita and INFN, Piazza Torricelli 2, I-56126 Pisa (Italy)
- Institut fuer Theoretische Physik, Universitaet Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)
We study the renormalization group evolution up to the fixed point of the lattice topological susceptibility in the 2D O(3) nonlinear {sigma} model. We start with a discretization of the continuum topological charge by a local charge density polynomial in the lattice fields. Among the different choices we propose also a Symanzik-improved lattice topological charge. We check step by step in the renormalization group iteration the progressive dumping of quantum fluctuations, which are responsible for the additive and multiplicative renormalizations of the lattice topological susceptibility with respect to the continuum definition. We find that already after three iterations these renormalizations are negligible and an excellent approximation of the fixed point is achieved. We also check by an explicit calculation that the assumption of slowly varying fields in iterating the renormalization group does not lead to a good approximation of the fixed point charge operator. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 467483
- Journal Information:
- Physical Review, D, Journal Name: Physical Review, D Journal Issue: 4 Vol. 55; ISSN PRVDAQ; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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