2017-12-18

UTAPwiki/セミナー/初期宇宙・相対論速報
Speaker: Shun-Pei Miao (National Cheng Kung Univ.) [from 1:30 PM]
Title: Deducing Cosmological Observables from the S-matrix
Abstract:
We study one loop quantum gravitational corrections to the long range force induced by the exchange of a massless scalar between two massive scalars. The various diagrams contributing to the flat space S-matrix are evaluated in a general covariant gauge and we show that dependence on the gauge parameters cancels at a point considerably before forming the full S-matrix, which is unobservable in cosmology. It is possible to interpret our computation as a solution to the effective field equations --- which could be done even in cosmology --- but taking account of quantum gravitational corrections from the source and from the observer.