Turing instability for nonlocal heterogeneous reaction-diffusion systems: A computer-assisted proof approach

This paper provides a computer-assisted proof for the Turing instability induced by heterogeneous nonlocality in reaction-diffusion systems. Due to the heterogeneity and nonlocality, the linear Fourier analysis gives rise to $\mathit{\text{strongly}}\mathit{\text{coupled}}$ infinite differential systems. By introducing suitable changes of basis as well as the Gershgorin disks theorem for infinite matrices, we first show that all $N$-th Gershgorin disks lie completely on the left half-plane for sufficiently large $N$. For the remaining finitely many disks, a computer-assisted proof shows that if the intensity $\delta$ of the nonlocal term is large enough, there is precisely one eigenvalue with positive real part, which proves the Turing instability. Moreover, by detailed study of this eigenvalue as a function of $\delta$, we obtain a sharp threshold ${\delta }^{\ast }$ which is the bifurcation point for Turing instability.