A second-order backward differentiation formula (BDF2) finite-volume discretization for a nonlinear cross-diffusion system arising in population dynamics is studied.
The numerical scheme preserves the Rao entropy structure and conserves the mass.
The existence and uniqueness of discrete solutions and their large-time behavior as well as the convergence of the scheme are proved.
The proofs are based on the G-stability of the BDF2 scheme, which provides an inequality for the quadratic Rao entropy and hence suitable a priori estimates.
The novelty is the extension of this inequality to the system case.
Some numerical experiments in one and two space dimensions underline the theoretical results.