To describe the dynamics of Hamiltonian systems with differential constraints, a
Hamiltonian vector field is projected onto the tangent planes of a distribution using a
symplectic structure to obtain a vector field whose phase flow preserves
distributions.
The possibility of implementing symplectic projection in degenerate cases is
considered when the restriction of the symplectic structure to the tangent planes of a
distribution is a degenerate 2-form. An application is presented for studying the
systems with one nonintegrable constraint of general form.
The method of symplectic projection is described in the framework of Dirac
structures.
Keywords
symplectic projection, nonholonomic point, almost-Dirac
structure