# Gravitational wave emission from the CMB and other thermal fields

## TL;DR

This paper calculates gravitational wave emission from quantum thermal sources like the CMB and stars, showing classical gravity treatment does not lead to ultraviolet divergence if sources are quantum.

## Contribution

It provides a novel calculation of gravitational wave power density from quantum thermal fields, including the CMB and stellar sources, highlighting the impact of classical gravity assumptions.

## Key findings

- No ultraviolet divergence in gravitational wave emission with quantum thermal sources
- Classical gravity treatment remains valid for thermal sources without divergence
- Quantitative estimates of gravitational wave power density from CMB and stars

## Abstract

We calculate the gravitational wave power density emitted by quantum thermal sources. As particular cases, we calculate the emission of gravitational waves from the cosmic microwave background and from stellar sources. We study how treating gravity classically affects the prediction of the thermal emission. We find that the predicted emitted gravitational wave radiation does not exhibit an ultraviolet divergence, even if gravity is treated classically, as long as the fields describing the thermal source are quantum mechanical.