1209.4694 (Ali Kaya)

Instanton Contributions to Cosmological Correlations    [PDF]

Ali Kaya

The path integral, which generates in-in correlation functions of a scalar field in a cosmological spacetime, is shown to admit nontrivial classical solutions as stationary phases. Although the solutions exist for Lorentzian signature, their contribution to the path integral is reminiscent that of the instantons in Euclidean field theories, and hence we give the same name to them. When the scalar potential has more than one locally stable vacua, the correlation functions receive contributions from all of them via these instantons, which is similar to tunneling. We present some explicit solutions for toy models and discuss possible implications of our results.

View original: http://arxiv.org/abs/1209.4694