Local Universal Splitting Integrators for Contact Hamiltonian Systems
Provides a theoretical foundation and practical numerical method for simulating dissipative systems with geometric structure, relevant to researchers in geometric numerical integration and contact geometry.
The paper develops a structure-preserving splitting framework for contact Hamiltonian systems, proving that the Lie algebra generated by strict and prolonged Hamiltonians is dense in the Lie algebra of smooth contact Hamiltonians, enabling universal contact splitting integrators.
Contact Hamiltonian systems extend symplectic Hamiltonian mechanics to dissipative settings while retaining geometric structure. We develop a structure-preserving splitting framework for contact Hamiltonian systems on $J^1(\mathbb{R}^n)$ based on two tractable classes of exact-contact subflows: strict contactomorphisms and prolonged diffeomorphisms. Our main theoretical result is that the Lie algebra generated by the corresponding strict and prolonged Hamiltonians contains all polynomial-in-$p$ Hamiltonians and is therefore dense, in the $C^r$ topology on compact sets, in the Lie algebra of smooth contact Hamiltonians. This yields a local universality result and contact splitting integrators built from exact strict and prolonged subflows. We then show how these subflows can be realized numerically by lifting symplectic integrators on $T^*\mathbb{R}^n$ and ODE integrators on $\mathbb{R}^n\times\mathbb{R}$. Finally, we illustrate the framework on a sequence of low-dimensional examples.