Special Session 7: Emergence and Dynamics of Patterns in Nonlinear Partial Differential Equations and Related Fields

Spiral Solutions Of The Koppel-Howard Lambda-Omega Reaction-Diffusion Equations

William C Troy
University of Pittsburgh
USA
Co-Author(s):    William C. Troy
Abstract:
Our investigation of logarithmic spirals is motivated by disparate experimental results: {\bf (i)} the discovery of logarithmic spiral shaped precipitate formation in chemical garden experiments. Understanding precipitate formation in chemical gardens is important since analogous precipitates form in deep ocean hydrothermal vents, where conditions may be compatible with the emergence of life. {\bf (ii)} the discovery that logarithmic spiral shaped waves of spreading depression can spontaneously form and cause macular degeneration in hypoglycemic chick retina. The role of reaction-diffusion mechanisms in spiral formation in these diverse experimental settings is poorly understood. To gain insight we use topological shooting to prove existence of 0-bump stationary logarithmic spiral solutions, and rotating logarithmic spiral wave solutions, of the Kopell-Howard lambda-omega reaction-diffusion model.