arXiv subjects

Tomasz Sobczak

Publications and source records attributed to Tomasz Sobczak.

4 recordsLinked to original sources

arXiv2025

$k$-contact Lie systems: theory and applications

This paper introduces a new class of Lie systems that are Hamiltonian relative to a $k$-contact manifold. We show that a recent distributional approach to $k$-contact manifolds along with a related $k$-contact Hamiltonian vector field notion allow us to understand relevant Lie systems as Hamiltonian relative to a $k$-contact manifold. Our procedure is more general than previously known methods with this aim. As a result, we find that a plethora of Lie systems related to control and physical problems can be considered in a natural manner as $k$-contact Lie systems. We study their $t$-dependent and $t$-independent constants of motion, master symmetries of higher order, and other properties of interest. Finally, we use our new techniques and findings to study PDE Lie systems with a compatible $k$-contact manifold, some of which become Hamilton--De Donder--Weyl equations.

math.DG↗

arXiv2025

Novel pathways in $k$-contact geometry

Our study of Goursat distributions originates new types of $k$-contact distributions and Lie systems with applications. In particular, families of generators for Goursat distributions on $\mathbb{R}^4, \mathbb{R}^5$ and $\mathbb{R}^6$ give rise to Lie systems and we characterise Goursat structures that are $k$-contact distributions. Our results are used to study the zero-trailer and other systems via Lie systems and $k$-contact manifolds. New ideas for the development of superposition rules via geometric structures and the characterisation of $k$-contact distributions are given and applied. Some relations of $k$-contact geometry with parabolic Cartan geometries are inspected.

math.DG↗

arXiv2025

Dirac structures in nonholonomic mechanics

The concept of a Dirac algebroid, which is a linear almost Dirac structure on a vector bundle, was designed to generate phase equations for mechanical systems with linear nonholonomic constraints. We apply it to systems with magnetic-like or gyroscopic potentials, that were previously described by means of almost Poisson structures. The almost Poisson structures present in the literature in this context were constructed using constraints, metrics and information about magnetic or gyroscopic potential present in the Hamiltonian function of the system. The Dirac algebroid we use is constructed out of constraints and canonical geometric structures of the underlying bundles and is universal in the sense that it is independent on the particular Hamiltonian or Lagrangian. We provide examples showing that using the same Dirac structure we can describe systems with different potentials, magnetic or mechanical, added freely to a function generating the dynamics.

math-ph↗

arXiv2025

Foundations on k-contact geometry

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.

math.DG↗