Travelling wave solutions in delayed cooperative systems

We establish the existence of travelling wave solutions for delayed cooperative recursions that are allowed to have more than two equilibria. We define an important extended real number that is used to determine the speeds of travelling wave solutions. The results can be applied to a large class of delayed cooperative reaction?diffusion models. We show that for a delayed Lotka?Volterra reaction?diffusion competition model, there exists a finite positive number that can be characterized as the slowest speed of travelling wave solutions connecting two mono-culture equilibria or connecting a mono-culture with the coexistence equilibrium.