Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 1998 | public
Journal Article

Multisymplectic Geometry, Variational Integrators, and Nonlinear PDEs

Abstract

This paper presents a geometric-variational approach to continuous and discrete mechanics and field theories. Using multisymplectic geometry, we show that the existence of the fundamental geometric structures as well as their preservation along solutions can be obtained directly from the variational principle. In particular, we prove that a unique multisymplectic structure is obtained by taking the derivative of an action function, and use this structure to prove covariant generalizations of conservation of symplecticity and Noether's theorem. Natural discretization schemes for PDEs, which have these important preservation properties, then follow by choosing a discrete action functional. In the case of mechanics, we recover the variational symplectic integrators of Veselov type, while for PDEs we obtain covariant spacetime integrators which conserve the corresponding discrete multisymplectic form as well as the discrete momentum mappings corresponding to symmetries. We show that the usual notion of symplecticity along an infinite-dimensional space of fields can be naturally obtained by making a spacetime split. All of the aspects of our method are demonstrated with a nonlinear sine-Gordon equation, including computational results and a comparison with other discretization schemes.

Additional Information

© 1998 Springer-Verlag. Received February 1997; this version, January 3, 1998. We would like to extend our gratitude to Darryl Holm, Tudor Ratiu and Jeff Wendlandt for their time, encouragement and invaluable input. Work of J. Marsden was supported by the California Institute of Technology and NSF grant DMS 96-33161. Work by G. Patrick was partially supported by NSERC grant OGP0105716 and that of S. Shkoller was partially supported by the Cecil and Ida M. Green Foundation and DOE. We also thank the Control and Dynamical Systems Department at Caltech for providing a valuable setting for part of this work.

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023