Zusammenfassung
Starting with the Chern-Simons formulation of (2+1)-dimensional gravity we
show that the gravitational interactions deform the Poincare symmetry of flat
space-time to a quantum group symmetry. The relevant quantum group is the
quantum double of the universal cover of the (2+1)-dimensional Lorentz group,
or Lorentz double for short. We construct the Hilbert space of two gravitating
particles and use the universal R-matrix of the Lorentz double to derive a
general expression for the scattering cross section of gravitating particles
with spin. In appropriate limits our formula reproduces the semi-classical
scattering formulae found by 't Hooft, Deser, Jackiw and de Sousa Gerbert.
Nutzer