Cosmology and Astrophysics of Axions and Axion-Like Particles David J. E. Marsh Axion theory and searches, IPhT CEA/Saclay, June 2015 (presentation figures to accompany lecture notes “Axion Cosmology,” Section 3+)

Fig. 1: Evolution of various quantities in the exact solution to the background evolution of an ALP in a radiation-dominated universe.

Fig. 2: ULA relic density from vacuum realignment in the broken PQ scenario with high scale inflation. Analytic approximation + backreaction.

Fig. 12b: CMB allowed region and misalignment for lower masses from numerical solution of EOMs. Backreaction is negligible.

Fig. 3a: QCD axion DM relic density from vacuum realignment in the broken PQ scenario with low scale inflation.

Fig. 3b: QCD axion DM relic density from vacuum realignment in the broken PQ scenario with high scale inflation.

Fig. 4: QCD axion DM relic density from vacuum realignment in the unbroken PQ scenario, including uncertainty from string decay.

Fig. 5a: The exact scale-dependent linear growth for an axion DM dominated universe at various k/(maH0)1/2. Growing mode.

Fig. 5b: The exact scale-dependent linear growth for an axion DM dominated universe at various k/(maH0)1/2. Decaying mode.

Fig. 6. Evolution of ULA overdensity in a realistic cosmology with 100% axion DM, compared to CDM. Computed with axionCAMB.

Fig. 7. ULA (solid) and WDM (dashed) transfer functions Fig. 7. ULA (solid) and WDM (dashed) transfer functions. WDM mass is computed to give the same value of the half-mode.

Fig. 14. The QCD axion in the broken PQ scenario is incompatible with observable tensor modes in the CMB.

Stellar Mass Supermassive Fig. 18: Black Hole superradiance constraints from 1411.2263 (Arvanitaki et al)