A theory of thin shells with orbiting constituents

The self-gravitating spherically symmetric thin shells built of orbiting particles are studied. Two new features are found. It is the minimal possible value for the angular momentum of particles, above which elliptic orbits become possible. And the coexistence of both the wormhole solutions and the elliptic or hyperbolic orbits for the same values of parameters (but different initial conditions). Possible applications of this results to astrophysics and quantum black holes are briefly discussed.