On
the Frequency Theorem for nonperiodic systems
with Roberta
Fabbri and Russell Johnson,
in: Dynamics,
Bifurcations and Control, 233-241,
Lecture
Notes
in Control and Information Sciences 273,
ed: Fritz
Colonius, Springer-Verlag, 2002.
Using
methods of the theory of nonautonomous linear
differential systems,
namely exponential dichotomies and rotation numbers, some
aspects of
Yakubovich's Frequency Theorem from periodic control systems are
generalized to systems with bounded measurable coefficients.
