N is number of particles
r_{0} is a geometrical parameter of torus
M_{c} is a central mass
M_{torus} is a torus mass
Section 2. Keplerian torus
Section 3. Trajectories of test particle in the inner potential of homogeneous circular torus and potential of the central mass
M_{torus} / M_{c} = 1
Section 4. Self-gravitating torus in the gravitational field of the central mass: N-body simulation
Change of torus cross-section due to self-gravitation for M_{torus} / M_{c} = 0.02, N = 16 384.
Initial conditions correspond to Keplerian torus with: