- Email: [email protected]
Quantum field theory in the infinite temperature limit
ABSTRACTS
OF
PAPERS
TO APPEAR
IN FUTURE
229
ISSUES
The Abelian Higgs model is the simplest available, but it has to be considered in general R, gauges in order to avoid infrared divergences. A full derivation of the appropriate Nielsen identities in such gauges is given. Certain restrictions on the class of allowed R, gauges are found, which resolve some difficulties in the use of such gauges in effective potential calculations. The one loop calculations are performed using Jackiw’s functional method. Explicit forms are obtained for the effective propagators required by Jackiw’s formalism, for our generalized R, gauges; the model may therefore provide a useful laboratory for other investigations. The extension of the identities to spontaneously broken non-Abelian gauge theories is given. Quantum Effects in the Gowdy T’ Cosmology. BEVERLY K. BERGER. Physics Department? Oakland University, Rochester, Michigan 48063. The Gowdy T3 cosmology is an exact solution to the vacuum Einstein equations interpreted to be a single polarization of gravitational waves propagating in an anisotropic, spatially inhomogeneous background. The classical behavior is reviewed and related to standard cosmological parameters. Canonical quantization of the dynamical degrees of freedom is reviewed. An adiabatic vacuum state is constructed. Adiabatic regularization is used to obtain nondivergent stress-energy tensor vacuum expectation values. Casimir energy terms due to T3 imposed discrete modes are evaluated. The vacuum expectation values are analyzed in early and late time limits and evaluated numerically. The regularized expectation value is used as a source for the classical background space-time in the spirit of semiclassical gravity. An entirely vacuum expectation value source term produces essentially the time reverse of the classical evolution. Classical stress-energy added to the source restores the classical behavior at late times only. The combined system collapses from infinite to small but nonzero volume and reexpands. The classical singularity is replaced by a symmetric bounce. Quantum Field Theory in the Infinite Temperature Limit. ALEXANDER N. JOURJINE. Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139. The T = co limit for renormalizable 4-dimensional Euclidean QFT is considered. A general argument is presented in three examples: 4”, QED, QCD. Using an expansion of the Green’s functions generating functional, it is shown that at T= co quantum dynamics generally becomes 3-dimensional. All superficially divergent diagrams survive at T = co and ensure renormalization of effective dynamics. The correction to naive dimensional reduction is studied; appearance of “electric” masses in QED and QCD is shown to be the result of such a correction. A curious symmetry of the generating functional in QED and QCD, its implications, and breaking by the thermal corrections of heavy modes are discussed.
Prinred
in Belgium
OF
PAPERS
TO APPEAR
IN FUTURE
229
ISSUES
The Abelian Higgs model is the simplest available, but it has to be considered in general R, gauges in order to avoid infrared divergences. A full derivation of the appropriate Nielsen identities in such gauges is given. Certain restrictions on the class of allowed R, gauges are found, which resolve some difficulties in the use of such gauges in effective potential calculations. The one loop calculations are performed using Jackiw’s functional method. Explicit forms are obtained for the effective propagators required by Jackiw’s formalism, for our generalized R, gauges; the model may therefore provide a useful laboratory for other investigations. The extension of the identities to spontaneously broken non-Abelian gauge theories is given. Quantum Effects in the Gowdy T’ Cosmology. BEVERLY K. BERGER. Physics Department? Oakland University, Rochester, Michigan 48063. The Gowdy T3 cosmology is an exact solution to the vacuum Einstein equations interpreted to be a single polarization of gravitational waves propagating in an anisotropic, spatially inhomogeneous background. The classical behavior is reviewed and related to standard cosmological parameters. Canonical quantization of the dynamical degrees of freedom is reviewed. An adiabatic vacuum state is constructed. Adiabatic regularization is used to obtain nondivergent stress-energy tensor vacuum expectation values. Casimir energy terms due to T3 imposed discrete modes are evaluated. The vacuum expectation values are analyzed in early and late time limits and evaluated numerically. The regularized expectation value is used as a source for the classical background space-time in the spirit of semiclassical gravity. An entirely vacuum expectation value source term produces essentially the time reverse of the classical evolution. Classical stress-energy added to the source restores the classical behavior at late times only. The combined system collapses from infinite to small but nonzero volume and reexpands. The classical singularity is replaced by a symmetric bounce. Quantum Field Theory in the Infinite Temperature Limit. ALEXANDER N. JOURJINE. Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139. The T = co limit for renormalizable 4-dimensional Euclidean QFT is considered. A general argument is presented in three examples: 4”, QED, QCD. Using an expansion of the Green’s functions generating functional, it is shown that at T= co quantum dynamics generally becomes 3-dimensional. All superficially divergent diagrams survive at T = co and ensure renormalization of effective dynamics. The correction to naive dimensional reduction is studied; appearance of “electric” masses in QED and QCD is shown to be the result of such a correction. A curious symmetry of the generating functional in QED and QCD, its implications, and breaking by the thermal corrections of heavy modes are discussed.
Prinred
in Belgium