1/N resolution to inflationary eta-problem
2012 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 713, no 4-5, 353-357 p.Article in journal (Refereed) Published
We observe that the dominant one loop contribution to the graviton propagator in the theory of N (N >> 1) light scalar fields phi(a) (with masses smaller than M-pI/root N) minimally coupled to Einstein gravity is proportional to N while that of graviton-scalar-scalar interaction vertex is N independent. We use this to argue that the coefficient of the R phi(2)(a) term appearing at one loop level is 1/N suppressed. This observation provides a resolution to the quantum eta-problem, that the slow-roll parameter eta receives order one quantum loop corrections for inflationary models built within the framework of scalar fields minimally coupled to Einstein gravity, for models involving large number of fields. As particular examples, we employ this to argue in favor of the absence of eta-problem in multi-field inflationary scenarios of M-flation and N-flation.
Place, publisher, year, edition, pages
2012. Vol. 713, no 4-5, 353-357 p.
IdentifiersURN: urn:nbn:se:uu:diva-181134DOI: 10.1016/j.physletb.2012.06.034ISI: 000306637900001OAI: oai:DiVA.org:uu-181134DiVA: diva2:553255