A connective stability result for interconnected passive systems

When a large scale system is formed from linear interconnections of a number of passive subsystems, a diagonal dominance condition on the interconnection matrix is known to ensure asymptotic stability. It is shown that the same condition ensures that stability is retained when a large class of nonlinearities, including nonlinearities with memory, is allowed in the interconnections. In particular, arbitrary distributed delays may be inserted without loss of stability.