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

Abstract

Abstract 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 C q 3 H 4 M p 4 $$ \frac{C}{q^3}\frac{H^4}{M_p^4} $$ log H μ $$ \left(\frac{H}{\mu}\right) $$ 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.

Keywords

• Classical Theories of Gravity
• Cosmology of Theories beyond the SM
• Models of Quantum Gravity