Criterion of stability of linear systems with variable coefficients and time lag: PMM vol. 36, n≗3, 1972, pp. 533–536

Abstract

A criterion of stability given by [1] for the linear systems of ordinary differential equations with variable coefficients, is extended to systems with lag. The explicit form of the quadratic functionals developed in [2] for the systems of differential equations with lag is used. These functionals play a role analogous to that of the Liapunov quadratic forms for the systems of ordinary differential equations. A criterion of stability of a nonlinear system of differential equations with lag is obtained in the manner analogous to that of [1].