With symplectic integrators, the aim of the game (among other things) is to try and preserve structure of the Hamiltonian - for e.g. conserved quantities like angular momentum. With specific focus on classical orbital mechanics, does anyone have experience with symplectic integration incorporating non-conserved forces? for e.g. Solar radiation, drag etc. I can't see a reason why they would have an effect on the integrator. Can anyone shed some light on this?
Symplectic integrators are only for conservative forces and cannot, in general, be used for non-conservative forces.
However, there have been attempts at generalizing such integrators to allow for non-conservative forces. Two recent examples I was able to find were
- Tsang, Galley, Stein and Turner Slimplectic Integrators: Variational Integrators for General Nonconservative Systems (2105) (arXiv link)1
- Luo & Guo Application of Explicit Symplectic Algorithms to Integration of Damping Oscillators (2011) (arXiv link)
The abstract to the Tsang et al paper mentions a few other of the authors' previous papers on the subject as well.
1. There is a public code (in Python) that shows their method.