The weak interaction and gravitational collapse

Recent developments in weak interaction physics as well as a more careful examination of previously known phenomena should yield a much clearer picture of the gravitational collapse of an evolved stellar core than has previously been possible. It is shown that the dominant neutrino-emitting process throughout much of the collapse is ordinary electron capture. The effects of neutral currents and the coherent scattering of neutrinos is discussed. A modified neutrino transport supernova model, whereby momentum transfer from neutrino scattering blows off the outer of a star while leaving a dense remnant, may be quite reasonable. The boundary between collapse and ejection is near rhoapprox.2times1011 g cm-3. Possible implications for origin of the cosmic rays and the heavy elements in the interstellar medium are discussed