Photino decay and the ionization of Lyman α clouds at large redshifts

Recent estimates of the hydrogen-ionizing photon flux at large redshifts, using data from Lyman α clouds, lead to values exceeding those expected from the quasar background. This excess flux is attributed to photons emitted by photinos surviving from the hot big bang. The photinos would need to have a rest-mass ∼ 50-100 eV and a lifetime ∼ 2.5 x 1024 s. Such photinos could provide the critical cosmological density and also dominate galaxies like the Milky Way. They would satisfy all known constraints from cosmology, astronomy and elementary particle physics. (author)