Non-existence of black-hole solutions for the electroweak Einstein-Dirac-Yang/Mills equations

We consider a static, spherically symmetric system of a Dirac particle interacting with classical gravity and an electroweak Yang-Mills field. It is shown that the only black-hole solutions of the corresponding coupled equations must be the extreme Reissner-Nordström solutions, locally near the event horizon. This work generalizes a series of papers published by F Finster, J Smoller and S-T Yau.