✦ LIBER ✦
Variational Multi-Time Green's Functions for Nonequilibrium Quantum Fields
✍ Scribed by Mohamed Benarous
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 345 KB
- Volume
- 269
- Category
- Article
- ISSN
- 0003-4916
No coin nor oath required. For personal study only.
✦ Synopsis
The time-dependent variational principle proposed by Balian and Ve ne roni is used to provide an optimal value of the generating functional for the multi-time Green's functions of a set of bosonic observables Q + . By restricting the two trial quantities to gaussian operators, an explicit formula is derived for the two-time Green's function, obtained to second order through the expansion in the sources. This leads to a tractable formalism for quantum fields out of equilibrium. As an illustration, we look at the finite temperature 8 4 -theory in curved space with coupling to gravity.