D-Stability and Delay-independent stability of homogeneous cooperative systems

We introduce a nonlinear definition of D-stability, extending the usual concept for positive linear time-invariant systems. We show that globally asymptotically stable, cooperative systems, homogeneous of any order with respect to arbitrary dilation maps are D-stable. We also prove a strong stability result for delayed cooperative homogeneous systems. Fi- nally, we show that both of these results also hold for planar cooperative systems without the restriction of homogeneity