F. Finster et al., Non-existence of black hole solutions for a spherically symmetric, static Einstein-Dirac-Maxwell system, COMM MATH P, 205(2), 1999, pp. 249-262
We consider for j = 1/2, 3/2, ... a spherically symmetric, static system of
(2j + 1) Dirac particles, each having total angular momentum j. The Dirac
particles interact via a classical gravitational and electromagnetic field.
The Einstein-Dirac-Maxwell equations for this system are derived. It is sho
wn that, under weak regularity conditions on the form of the horizon, the o
nly black hole solutions of the EDM equations are the Reissner-Nordstrom so
lutions. In other words, the spinors must vanish identically. Applied to th
e gravitational collapse of a "cloud" of spin-1/2-particles to a black hole
, our result indicates that the Dirac particles must eventually disappear i
nside the event horizon.