Spin-Statistics Connexion, Neutrinos, and Big Bang Nucleosynthesis

Abstract

We show how the ${}^4$He-abundance in the early Universe can be used to demonstrate that macroscopic samples of neutrinos in thermal equilibrium are indeed distributed according to Fermi-Dirac statistics.

Comments: 9 pages in plain LaTeX, 3 postscript figures in a separate tarred compressed uuencoded file. Revised version with minor quantitative changes. Figure 1 includes now a study of all light elements. Conclusions unchanged. To be published in Astroparticle Physics