Tailoring diffusion in analogue spacetimes

Diffusive transport is characterized by the scaling law $(length)^{2}\propto(time)$. In this letter we show that this relationship is significantly altered in curved analogue spacetimes. This circumstance provides an opportunity to tailor diffusion: by a suitable design of the analogue metric, it is possible to create materials where diffusion is either faster or slower than in normal media, as desired. This prediction can in principle be tested experimentally with optical analogues, curved graphene sheets, etc. - indeed with any analogue spacetime.