Fig. 3.

Clustered spiky steady state of (1.2) for ${\mathit{\epsilon }}^2=0.0001,D=0.002,\mathit{\mu }(|y|)=1+{5|y|}^2$. Because smaller diffusivities are chosen, we now get more spikes than in Figs. 1 and 2. Shown is a $(4+1)$-spike cluster consisting of 4 spikes on a regular polygon plus a spike in the centre. The activator A is displayed in two three-dimensional surface plots from different perspectives in the top two graphs and its projection to the domain plane is shown in the bottom graph