PT Journal
AU Ferreiro, A
   Navarro-Salas, J
   Pla, S
TI R-summed form of adiabatic expansions in curved spacetime
SO Physical Review D
JI Phys. Rev. D
PY 2020
BP 105011
EP 12pp
VL 101
IS 10
DI 10.1103/PhysRevD.101.105011
LA English
AB The Feynman propagator in curved spacetime admits an asymptotic (Schwinger-DeWitt) series expansion in derivatives of the metric. Remarkably, all terms in the series containing the Ricci scalar R can be summed exactly. We show that this (nonperturbative) property of the Schwinger-DeWitt series has a natural and equivalent counterpart in the adiabatic (Parker-Fulling) series expansion of the scalar modes in an homogeneous cosmological spacetime. The equivalence between both R-summed adiabatic expansions can be further extended when a background scalar field is also present.
ER