Constraining axion stimulated emission using the CMB power spectra measurements and the interplay with current CMB constraints on the reionization epo

I aim to constrain the stimulated emission of axions from the CMB power spectra using a cosmological Boltzmann code, CLASS, and comparing to the measurements made by Planck in order to constrain the allowed parameter space for axion stimulated emission using the Markov-Chain-Monte-Carlo analysis code, MontePython.

The stimulated emission of axions provides an additional source of energy that can reheat, excite or ionize the Intergalactic Medium (IGM). Any source of energy injection into the IGM could lead to the production of more electrons, which increases the probability of the CMB photons and electrons interacting via Thomson Scattering. This leads to an overall dampening of the CMB anisotropies and more specifically, the polarization (EE) CMB power spectrum.

The reionization optical depth obtained from the CMB polarization spectra favours reionization at higher redshifts than what is constrained by the measurement of the Gunn-Peterson trough of a Quasar at z~6. This could present an interesting interplay between the current model of the reionization epoch from early star formation and additional reionization sources from axions. I am currently comparing the optical depth from axion stimulated emission to the optical depth derived from the CMB EE power spectra measurements by Planck. From this, I should be able to derive the allowed parameter space derived from the bound on the reionization optical depth. I am also investigating if the EE power spectrum will change if there is a redshift dependence on the energy injection for a given optical depth. This exercise will help to determine if I need to use CLASS and MontePython in the analysis.