Equilibria of an anisotropic nonlocal interaction equation: Analysis and numerics
In this paper, we study the equilibria of an anisotropic, nonlocal aggregation equation with nonlinear diffusion which does not possess a gradient flow structure. Here, the anisotropy is induced by an underlying tensor field. While anisotropic forces cannot be associated with a potential in general and stationary solutions of anisotropic aggregation equations generally cannot be regarded as minimizers of an energy functional, we derive equilibrium conditions for stationary line patterns in the setting of spatially homogeneous tensor fields which can be regarded as the minimizers of a regularised energy functional depending on a scalar potential. In particular, this dimension reduction allows us to study the associated one-dimensional problem instead of the two-dimensional setting. For spatially homogeneous tensor fields, we show the existence of energy minimisers, establish Γ-convergence of the regularised energy functionals as the diffusion coefficient vanishes, and prove the convergence of minimisers of the regularised energy functional to minimisers of the non-regularised energy functional. Further, we investigate properties of stationary solutions on different domains. Finally, we prove weak convergence of a numerical scheme for the numerical solution of the anisotropic, nonlocal aggregation equation with nonlinear diffusion and any underlying tensor field, and show numerical results.
READ FULL TEXT