A homeomorphism between observable pairs and conditioned invariant subspaces

P. A. Fuhrmann, U. Helmke

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


A bijective correspondence between similarity classes of observable systems (C, A) and n-codimensional conditioned invariant subspaces of a pair (script C sign, script A sign) is constructed that leads to a homeomorphism of the spaces. This is applied to the parametrization of inner functions of fixed McMillan degree. Proofs using state space methods as well as using polynomial models are given.

Original languageEnglish
Pages (from-to)217-223
Number of pages7
JournalSystems and Control Letters
Issue number5
StatePublished - 1 Jan 1997


  • Conditioned invariant subspaces
  • Geometric control
  • Inner functions
  • Parametrization problems

ASJC Scopus subject areas

  • Control and Systems Engineering
  • General Computer Science
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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