| dc.description.abstract | Quantum one-loop corrections to various propagators on a de-Sitter background have been extensively
studied by Woodard, Park, Prokopec and collaborators . In the current master thesis, we investigate
the one-loop corrections to the graviton propagator due to the presence of massive non-minimally
coupled scalar fields. Our background geometry is the open conformal coordinate patch of de-Sitter
spacetime. We define the graviton to be a small fluctuation around the de-Sitter background while
the massive non-minimally coupled scalar propagator is the so-called Chernikov-Tagirov propagator.
Two Feynman diagrams contribute to the self-energy of the graviton. The quartic contribution,
which corresponds to local contribution, has already been renormalized by R. Koelewijn (”Gravitons
on de Sitter modified by quantum fluctuations of a nonminimally coupled massive scalar. MS thesis.
2017.” [1]). We focus our attention to the cubic contribution (non-local) which is proportial to the TT
correlator computed by R.Koelewijn. Our aim is to reorganize the expression for the TT correlator
in such a way that it will allow us to renormalize it, using dimensional regularization scheme. In
particular, we localize the divergences that appear onto local δ-function terms, and subtract them by
using the local counterterms R2 and C2 introduced in the 80’s by G. t’Hooft and M.Veltman. Since
our final goal is to quantum correct the linearized Einstein’s equations, the final form of the graviton
self energy should contain only terms which are integrable in D = 4 dimensions and finite. | |
