Renormalization procedure for the classical lattice computation of inflationary SIGWs

Develop a consistent procedure to properly renormalize the classical lattice computation of the inflationary second‑order gravitational‑wave spectrum and carefully derive the corresponding renormalized spectrum.

Background

The authors sketch the structure of the inflationary SIGW calculation and note that naive classical evaluations exhibit divergences, necessitating regularization and renormalization. In their preliminary implementation they set an arbitrary cutoff to obtain an order‑of‑magnitude estimate.

They explicitly state that both a careful derivation of the renormalized inflationary spectrum and a consistent renormalization procedure for the classical lattice output remain to be completed. Addressing this would clarify the physical inflationary contribution and enable robust comparisons with post‑reheating signals.