1. G. Domokos, M. M. Janson andS. Kövesi-Domokos: JHU preprint, to be published inNature.
2. F. Gürsey:Ann. of Phys.,23, 211 (1963). See alsoR. Penrose:Proc. Roy. Soc.,284 A, 204 (1965).
3. For a review see,e.g.,E. S. Abers andB. W. Lee:Phys. Rep.,9, 1 (1973). Unless otherwise stated we follow their notation with obvious modification in order to accommodate an arbitrary space-time metric.
4. B. K. Harrison, K. S. Thorne, M. Wakano andJ. A. Wheeler:Gravitational Theory and Gravitational Collapse, Chap. 3, 10 (Chicago, Ill., 1965).
5. Including the effects of internuclear forces will not qualitatively change our results. Nuclei will disappear at a lower density than that we have considered. This will have the effect of increasing the radius of our «core».