Key points are not available for this paper at this time.
In order that the effect of graviation of the thermal background neutrinos on the expansion of the universe not be too severe, their mass should be less than 8 eVc2.Received 17 July 1972DOI:https://doi.org/10.1103/PhysRevLett.29.669©1972 American Physical Society
Cowsik et al. (Mon,) studied this question.