Before revision: We consider the classical problem of optimal portfolio construction with the constraint that no short position is allowed, or equivalently the valid equilibria of multispecies Lotka-Volterra equations , in the special case where the interaction matrix is of unit rank, corresponding to a single-resource MacArthur model .
After revision: We consider the classical problem of optimal portfolio construction with the constraint that no short position is allowed, or equivalently the valid equilibria of multispecies Lotka-Volterra equations , in the special case where the interaction matrix is of unit rank, corresponding to species competing for a common resource .