[en] The proposal to search for relic neutrinos through their absorption effect on the neutrino cosmic ray flux is discussed. It is shown that within the context of big band cosmology, detection of relic neutrinos with this method appears very unlikely but not impossible
Kolb, E.W.; Turner, M.S.; Lindley, D.; Olive, K.; Seckel, D; p. 107-111; ISBN 0-226-45032-5; ; 1986; p. 107-111; University of Chicago Press; Chicago, IL (USA)