Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Contribution to the Extragalactic Gamma-ray Background from the Cascades
  of Very-high Energy Gamma Rays from Blazars   As very high energy (VHE) photons propagate through the extragalactic
background light (EBL), they interact with the soft photons and initiate
electromagnetic cascades of lower energy photons and electrons. The collective
intensity of a cosmological population emitting at VHEs will be attenuated at
the highest energies through interactions with the EBL and enhanced at lower
energies by the resulting cascade. We calculate the cascade radiation created
by VHE photons produced by blazars and investigate the effects of cascades on
the collective intensity of blazars and the resulting effects on the
extragalactic gamma-ray background. We find that cascade radiation greatly
enhances the collective intensity from blazars at high energies before turning
over due to attenuation. The prominence of the resulting features depends on
the blazar gamma-ray luminosity function, spectral index distribution, and the
model of the EBL. We additionally calculate the cascade radiation from the
distinct spectral sub-populations of blazars, BL Lacertae (BL Lacs) objects and
flat-spectrum radio quasars (FSRQs), finding that the collective intensity of
BL Lacs is considerably more enhanced by cascade radiation than that of the
FSRQs. Finally, we discuss the implications that this analysis and upcoming
Fermi observations could have for the nature of the EBL, the evolution of
blazars, blazar spectra, and other sources of gamma-ray radiation.

9
The categories of this paper are: nlin
3
The categories of this paper are: physics
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn