... A strict lower-limit flux for the evolving extragalactic background light
(and in particular the cosmic infrared background) has been calculated up to
redshift of 5. The computed flux is below the existing upper limits from direct
observations, and in agreement with all existing limits derived from very-high
energy gamma-ray observations. The corrected spectra are still in agreement
with simple theoretical predictions. The derived strict lower-limit EBL flux is
very close to the upper limits from gamma-ray observations. This is true for
the present day EBL but also for the diffuse flux at higher redshift. If future
detections of high redshift gamma-ray sources require a lower EBL flux than
derived here, the physics assumptions used to derive the upper limits have to
be revised. The lower-limit EBL model is not only needed for absorption
features in AGN and other gamma-ray sources but is also essential when
alternative particle processes are tested, which could prevent the high energy
gamma-rays from being absorbed. It can also be used for a quaranteed
interaction of cosmic-ray particles. The model is available online.Comment: 12 pages, 6 figures, accepted by A&
