Explaining Large Electromagnetic Logarithms from Loops of Inflationary Gravitons

TL;DR

This paper investigates the origin of large electromagnetic logarithms from inflationary graviton loops, using recent advances in de Sitter quantum field theory, and explores their implications for photon wave functions and Coulomb potential corrections.

Contribution

It reanalyzes single graviton loop effects on electromagnetic fields in de Sitter space, connecting them to curvature-dependent renormalization and challenging the interpretation of certain logarithmic factors.

Findings

Large inflationary logarithms can be explained by curvature-dependent renormalization.

1-loop corrections to photon wave function and Coulomb potential are revisited with new theoretical tools.

The $ ext{ln}(Hr)$ factor in Coulomb potential may not be a leading logarithm effect.

Abstract

Recent progress on nonlinear sigma models on de Sitter background has permitted the resummation of large inflationary logarithms by combining a variant of Starobinsky's stochastic formalism with a variant of the renormalization group. We reconsider single graviton loop corrections to the photon wave function, and to the Coulomb potential, in light of these developments. Neither of the two 1-loop results have a stochastic explanation, however, the flow of a curvature-dependent field strength renormalization explains their factors of $\ln(a)$. We speculate that the factor of $\ln(Hr)$ in the Coulomb potential should not be considered as a leading logarithm effect.