Small-scale fluctuations in the cosmic x-ray background: A power spectrum approach

Equations to investigate fluctuations in cosmic x-ray background radiation due to pointlike sources at high-redshift are formulated in a systematic way. The angular power spectrum of x-ray background fluctuations is investigated from large scales to small scales in various cosmological models such as open universe models and models with the cosmological constant, assuming a simple evolution model of the sources. The effect of the epoch-dependent bias is demonstrated for small-angle fluctuations. The contribution from shot noise fluctuations is also discussed.