Fine-scale anisotropy of cosmic γ-ray background to identify the underlying generation process

The study of the intrinsic anisotropies of the extragalactic γ-ray background is of cosmological importance. As the first step to investigate the anisotropies, we introduce new evolutionary results of the active galaxies and calculate the fine-scale anisotropy because of the possible contribution from the active galactic nucleus (AGN) model. By use of Monte Carlo simulations, we discuss the fine-scale fluctuation patterns and propose that these patterns or anisotropies form a unique test for the AGN generation mechanism. We also suggest that the best energy range to test the AGN model is E₀ ~∼ 10 MeV for the new-generation high-resolution telescopes.