Quantum backreaction in cosmology


Prokopec, T. (2009). Quantum backreaction in cosmology. Perimeter Institute. https://pirsa.org/09120019


Prokopec, Tomislav. Quantum backreaction in cosmology. Perimeter Institute, Dec. 01, 2009, https://pirsa.org/09120019


          @misc{ pirsa_PIRSA:09120019,
            doi = {10.48660/09120019},
            url = {https://pirsa.org/09120019},
            author = {Prokopec, Tomislav},
            keywords = {Cosmology},
            language = {en},
            title = {Quantum backreaction in cosmology},
            publisher = {Perimeter Institute},
            year = {2009},
            month = {dec},
            note = {PIRSA:09120019 see, \url{https://pirsa.org}}

Tomislav Prokopec Utrecht University


The problem of the quantum backreaction in expanding spaces is an old, as yet unresolved, question. In this talk I will consider the one-loop backreaction of a massless scalar which couples to the Ricci scalar in an expanding space with constant deceleration. I will show that the infrared divergences, which generically plague the one loop stress energy, can be removed by matching onto an earlier radiation era. An insignificant backreaction occurs, unless the coupling to the Ricci scalar is negative. Similar results hold for the graviton backreaction.