Stationary Bound States of Dirac Particles in Collapsar Fields
  Stationary bound states of elementary spin 1/2 particles that do not decay with time are obtained for a Schwarzschild gravitational field using a self-conjugate Hamiltonian with a flat scalar product at small values of gravitational coupling constant. In order to obtain a discrete energy spectrum, we introduce a boundary condition such that the azimuthal current density of Dirac particles on the "event horizon" is zero. The results can lead to revisiting some concepts of the standard cosmological model related to the evolution of the universe and interaction of collapsars with surrounding matter. 
M.V. Gorbatenko, V.P. Neznamov
gr-qc hep-th