Models of the Contribution of Blazars to the Anisotropy of the
  Extragalactic Diffuse Gamma-ray Background
  We study the relation between the measured anisotropies in the extragalactic
diffuse gamma-ray background (DGRB) and the DGRB spectral intensity, and their
potential origin from the unresolved blazar population. Using a
physical-evolution model for blazars with a luminosity dependent evolution
(LDDE) and an observationally-determined luminosity-dependent blazar spectral
energy distribution (SED), we find that blazars can account for the observed
anisotropy of the DGRB consistent with their observed source-count
distribution, but are in turn constrained in contributing significantly to the
observed DGRB intensity. For the best-fit LDDE model accounting for the DGRB
anisotropy and source-count distribution, blazars only contribute
5.7^{+2.1}_{-1.0}% (68% CL) of the DGRB intensity above 1 GeV. Requiring a
higher fraction of the DGRB intensity contribution by blazars overproduces the
DGRB anisotropy, and therefore blazars in the LDDE+SED-sequence model cannot
simultaneously account for the DGRB intensity as well as anisotropy. We discuss
the limitations of LDDE models. However, these models do not require the many
unjustified and observationally-inconsistent simplifying
assumptions---including a single power law for all blazar spectra and a simple
broken power-law model for their source-count distribution---that are present
in much previous work.
