Physics (Internal)

Diffusion-limited Mutualism in Microbes

This event is part of the Preliminary Oral Exam.

Examining Committee: Kiril Korolev, Pankaj Mehta, Shyam Erramilli and Kevin Black

Abstract: Microbes cooperate by swapping diffusive metabolites to form robust and fully functional societies. Contrary to intuition from game theory, we find that metabolite diffusivity tends to inhibit stable microbial mutualism. Increasing public goods diffusivity beyond a critical point completely destroys coexistence, leading species extinction via a nonequilibrium phase transition. Analytical results for the critical diffusivity and typical domain sizes are computed based how public good diffusivity renormalizes the strength of selection and thus should be applicable to a variety of more complex models. In addition, fitness nonlinearities suppress mutualism and favor the species producing slower nutrients.