## Abstract

It is proved that invertible operators on a Krein space which have an invariant maximal uniformly positive subspace and map its orthogonal complement into a nonnegative subspace allow polar decompositions with additional spectral properties. As a corollary, several classes of Krein space operators are shown to allow polar decompositions. An example in a finite dimensional Krein space shows that there exist dissipative operators that do not allow polar decompositions.

Original language | English |
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Pages (from-to) | 83-91 |

Journal | Integral Equations and Operator Theory |

Volume | 56 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2006 |