Foundations on k-contact geometry
Javier de Lucas, Xavier Rivas, Tomasz Sobczak
TL;DR
The paper develops foundations of $k$-contact geometry by introducing a distributional framework: $k$-contact distributions as kernels of $k$-valued 1-forms that are distributionally maximally non-integrable and admit locally $k$ commuting Lie symmetries, linking them to Engel, Goursat, and related distributions. It establishes a deep structural equivalence: a distribution is $k$-contact iff it is maximally non-integrable and locally spanned by $k$ Lie-symmetry fields supplementing the distribution, with Reeb fields generating the symmetry algebra and commuting. It then develops polarisation theory, Darboux-type theorems, and jet-bundle representations (e.g., $J^1(N,E)$) to provide canonical local models, and connects $k$-contact manifolds to presymplectic and $k$-symplectic covers, enabling Hamiltonian formalisms via HDW equations and Lie symmetries for first-order PDEs, including Hamilton–Jacobi and Dirac-type equations. The work also extends to compact examples, Weinstein-type conjectures in the $k$-contact setting, and practical applications to non-holonomic and control systems, while offering multiple routes for symplectification and submanifold theory within this richer geometric framework.
Abstract
k-Contact geometry is a generalisation of contact geometry to analyse field theories. We develop an approach to k-contact geometry based on distributions that are distributionally maximally non-integrable and admit, locally, k commuting supplementary Lie symmetries: the k-contact distributions. We related k-contact distributions with Engel, Goursat and other distributions, which have mathematical and physical interest. We give necessary topological conditions for the existence of globally defined Lie symmetries, k-contact Lie groups are defined and studied, and we study and propose a k-contact Weinstein conjecture for co-oriented k-contact manifolds. Polarisations for k-contact distributions are introduced and it is shown that a polarised k-contact distribution is locally diffeomorphic to the Cartan distribution of the first-order jet bundle over a fibre bundle of order k. We relate k-contact manifolds to presymplectic and k-symplectic manifolds on fibre bundles of larger dimension and define types of submanifolds in k-contact geometry. We study Hamilton-De Donder-Weyl equations in Lie groups for the first time. A theory of k-contact Hamiltonian vector fields is developed, and we describe characteristics of Lie symmetries for first-order partial differential equations in a k-contact Hamiltonian manner. We use our techniques to analyse Hamilton-Jacobi and Dirac equations. Other potential applications of k-contact distributions to non-holonomic and control systems are briefly described.
