11. Moreover any such isomorphism is induced by some diffeomorphism . 12. The symmetry is called general covariance or diffeomorphism invariance. 13. By the Alexander trick, such a diffeomorphism extends to the disk itself. 14. For each compact manifold, the diffeomorphism group is a regular Lie group. 15. The diffeomorphism group are flows with vector fields absolutely integrable in Sobolev norm: 16. Moreover, differential topology does not restrict itself necessarily to the study of diffeomorphism . 17. The ( orientation-preserving ) diffeomorphism group of the circle is pathwise connected. 18. In mathematics, a diffeomorphism is an isomorphism in the category of smooth manifolds. 19. The spatial diffeomorphism constraint with a Hamiltonian gives a Hamiltonian with its smearing shifted, 20. Here, the constraints are the diffeomorphism constraints.
