Canards in a bottleneck

In this paper we investigate the stationary profiles of a nonlinear Fokker-Planck equation with small diffusion and in- outflow boundary conditions. We consider corridors bottleneck whose width has global nondegenerate minimum in interior. limit are obtained constructively by using methods from geometric singular perturbation theory (GSPT). identify three main types corresponding to: (i) high density domain layer at entrance, (ii) low exit, (iii) transitions to inside layers entrance exit. Interestingly, solutions last type involve canard generated narrowest point bottleneck. obtain detailed bifurcation diagram these terms rates. The analytic results based on GSPT further corroborated computational experiments investigating bottlenecks variable width.