RT Journal Article T1 Thermal-energy in robertson-walker universes A1 Ruiz Ruiz, Fernando AB The covariant functional Schrödinger formalism is used to study thermal equilibrium for a scalar field in Robertson Walker spacetimes. It is found that thermal equilibrium can be maintained for field masses, coupling constants and geometries satisfying a given differential equation, of which the massless conformally coupled case is a solution, but not the only one. The thermal energy is computed; it contains a term which for particular geometries, such as de Sitter spacetime, grows in time. PB Elsevier Science Bv SN 0370-2693 YR 1989 FD 1989-03-23 LK https://hdl.handle.net/20.500.14352/59051 UL https://hdl.handle.net/20.500.14352/59051 NO Copyright © 1989 Published by Elsevier B.V. DS Docta Complutense RD 5 abr 2025