One-loop corrections to the primordial tensor spectrum from massless isocurvature fields

We study one-loop corrections to the two-point correlation function of tensor perturbations in primordial cosmology induced by massless spectator matter fields. Using the Schwinger-Keldysh formalism in cosmological perturbation theory, we employ dimensional regularization and cutoff regularization t...

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Bibliographic Details
Main Author: Tan, Hai Siong
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2020
Subjects:
Online Access:https://hdl.handle.net/10356/145595
Description
Summary:We study one-loop corrections to the two-point correlation function of tensor perturbations in primordial cosmology induced by massless spectator matter fields. Using the Schwinger-Keldysh formalism in cosmological perturbation theory, we employ dimensional regularization and cutoff regularization to study the finite quantum corrections at one-loop arising from isocurvature fields of the massless scalar, fermion and abelian gauge field which are freely propagating on the FRW spacetime. For all cases, we find a logarithmic running of the form Cq3H4M4p log (Hμ) where C is a negative constant related to the beta function, H is the Hubble parameter at horizon exit and μ is the renormalization scale.