IMPACT OF INHOMOGENEOUS REIONIZATION ON COSMIC MICROWAVE BACKGROUND ANISOTROPY

Ir is likely that the reionization of the Universe did not occur homog eneously. Using a model that associates ionized patches with overdense regions, we find that the resulting cosmic microwave background (CMB) anisotropy power spectrum peaks at angular scales corresponding to th e extent of the ionized regions, and has a width that reflects the cor relations between them. There is considerable uncertainty in the ampli tude. Neglecting inhomogeneous reionization in the determination of co smological parameters from high resolution CMB maps may cause signific ant systematic error.