Hassibi, B.Sayed, Ali H.Kailath, T.2017-12-192017-12-192017-12-19199310.1109/CDC.1993.325855https://infoscience.epfl.ch/handle/20.500.14299/143037We show that several applications considered in the context of Hoo filtering and game theory, risk sensitive control and estimation, follow as special cases of the Krein space Kalman filter. We show that these problems can be cast into the problem of calculating the stationary points of certain second order forms: and that by considering appropriate state space models and error Gramians, we can use the Krein space Kalman filter to recursively compute these stationary points and to study their properties.text::conference output::conference proceedings::conference paper