Spectro-spatial evolution of the CMB I: discretisation of the thermalisation Green’s function

Publication
Author

Jens Chluba, Tom Kite and Andrea Ravenni

Published

October 17, 2022

This paper is the first in a series of three papers on the spectro-spatial evolution of the CMB. In this paper we present a new method to solve the Kompaneets equation for the CMB photon distribution function. The method constructs a discrete set of characteristic photon spectra, which allows numerical solvers to reduce the size of the equation set by two or three orders of magnitude while also providing better physical insight to the system. This paper motivates the discretisation and shows the new method converges to expected results for the average spectrum.

Arxiv preprint

Published version

The distorted CMB photon spectrum as seen today arising from energy injection at different redshifts. The distorted CMB photon spectrum as seen today arising from energy injection at different redshifts.