Implications of the cosmic infrared background for light production and the star formation history in the Universe

The Cosmic Background due to the integrated radiation from galaxies over th e whole life of the Universe is reviewed. We find that this background is w ell constrained by measurements. The total power in the background is in th e range 60-93 nWm(-2)sr(-1). The data show the existence of a minimum separ ating the direct stellar radiation from the infrared part due to radiation reemitted by dust. This reemitted dust radiation is about 1-2.6 time the ba ckground power in the optical/near-IR thus much larger than the same ratio measured locally (30%). The far-infrared and submillimeter background is li kely to be dominated by redshifted infrared galaxies. The long wavelength s pectrum of the background being significantly flatter than the spectrum of these galaxies it strongly constrains the far-infrared radiation production rate history which must increase by a factor larger than 10 between the pr esent time and a redshift 1 and then stays rather constant at higher redshi ft, contrary to the ultraviolet radiation production rate which decreases r apidly. Several models of galaxy evolution have been proposed to explain the submil limeter background. In this paper we do not propose a new model; we systema tically explore the allowed range of evolution histories allowed by the dat a. If infrared galaxies are mostly powered by starbursts as indicated by re cent observations, this infrared production history reflects the history of starformation in the Universe.