Phase space carries closed non-degenerate 2-form ω = dp_i ∧ dq_i; Hamiltonian flow preserves ω (Liouville). Basis of symplectic geometry.
Phase space carries closed non-degenerate 2-form ω = dp_i ∧ dq_i; Hamiltonian flow preserves ω (Liouville). Basis of symplectic geometry.