December 9 2015 Wednesday 15:30
Nihan Katırcı, Boğaziçi University
Inflation and current accelerated expansion of the universe a’ la the Stueckelberg mechanism

Abstract: The higher the scale the tighter the upper bounds on the photon mass, which demonstrates also that even an extremely small value of the photon mass (roughly < 10^(-30) eV ) can have a considerable effect on the evolution of the universe. In this talk, after a short review on evolution of the universe from Big Bang up to now, we will focus on the two accelerated expansionary phases of its evolution. As an alternative way of inducing accelerated expansion rather than using two different mechanisms, say the inflaton or dark energy sources in GR, we will show that a massive non-minimally coupled photon that gains its mass by the Stueckelberg mechanism in curved space-time can alone lead a cosmological model in which the universe goes through a deceleration phase sandwiched by two different accelerated expansion phases. This feature of solution disappears if the mass of the Stueckelberg field is null.

Reference: O. Akarsu, M. Arık, N.Katırcı, and M. Kavuk, JCAP 07 (2014) 009, arXiv:1404.0892.