Soft Graviton effects on Gauge theories in de Sitter Space

TL;DR

This paper investigates how soft gravitons influence gauge theories in de Sitter space, revealing universal screening of gauge couplings and gauge-invariant relative scaling, with implications for cosmic microwave background observations.

Contribution

It extends previous work by evaluating quantum equations of motion in gauge theories, showing gauge coupling screening and gauge-invariant scaling exponents in de Sitter space.

Findings

Gauge coupling constants are universally screened and diminish over time.

Lorentz invariance is preserved, and the speed of light is not renormalized at one-loop.

Relative scaling exponents are gauge independent and potentially observable.

Abstract

We extend our investigation of soft graviton effects on the microscopic dynamics of matter fields in de Sitter space. We evaluate the quantum equation of motion in generic gauge theories. We find that the Lorentz invariance can be respected and the velocity of light is not renormalized at the one-loop level. The gauge coupling constant is universally screened by soft gravitons and diminishes with time. These features are in common with other four dimensional field theories with dimensionless couplings. In particular the couplings scale with time with definite scaling exponents. Although individual scaling exponents are gauge dependent, we argue that the relative scaling exponents are gauge independent and should be observable. We also mention soft graviton effects on cosmic microwave background.