Photon Frequency Diffusion Process
Abstract
We introduce a stochastic multi-photon dynamics on reciprocal space. Assuming isotropy, we derive the diffusion limit for a tagged photon to be a nonlinear Markov process on frequency. The nonlinearity stems from the stimulated emission. In the case of Compton scattering with thermal electrons, the limiting process describes the dynamical fluctuations around the Kompaneets equation. More generally, we construct a photon frequency diffusion process which enables to include nonequilibrium effects. Modifications of the Planck Law may thus be explored, where we focus on the low-frequency regime.
- Publication:
-
Journal of Statistical Physics
- Pub Date:
- October 2022
- DOI:
- 10.1007/s10955-022-02960-0
- arXiv:
- arXiv:2202.08660
- Bibcode:
- 2022JSP...189....4O
- Keywords:
-
- Diffusion;
- Kompaneets equation;
- Non-equilibrium;
- Langevin equation;
- Condensed Matter - Statistical Mechanics;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 30 pages, 8 figures