Gauge-invariant effective potential: Equilibrium and nonequilibrium aspects
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)
We propose a gauge-invariant formulation of the effective potential in terms of a gauge-invariant order parameter, for the Abelian Higgs model. The one-loop contribution at zero and finite temperature is computed explicitly, and the leading terms in the high temperature expansion are obtained. The result is contrasted with the effective potential obtained in several covariant gauge-fixing schemes, and the gauge-invariant quantities that can be reliably extracted from these are identified. It is pointed out that the gauge-invariant effective potential in the one-loop approximation is complex for {ital all} {ital values} of the order parameter between the maximum and the minimum of the tree level potential, both at zero and nonzero temperatures. The imaginary part is related to long-wavelength instabilities towards phase separation. We study the real-time dynamics of initial states in the spinodal region, and relate the imaginary part of the effective potential to the growth rate of equal-time gauge-invariant correlation functions in these states. We conjecture that the spinodal instabilities may play a role in nonequilibrium processes {ital inside} the nucleating bubbles if the transition is first order. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 286251
- Journal Information:
- Physical Review, D, Vol. 54, Issue 2; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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