The diffuse extragalactic background light (EBL) is all the accumulated radiation in the universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs).
The EBL is part of the diffuse extragalactic background radiation (DEBRA), which by definition covers the entire electromagnetic spectrum.
[6] Recently, two independent groups using different technique have claimed the detection of the EBL in the optical with no contamination from zodiacal light.
The galaxy evolution is inferred here using some quantity derived from observations such as the star formation rate density of the universe.
[23][24][25][26] (iv) Evolution of the galaxy populations that is directly observed over the range of redshifts that contribute significantly to the EBL.