Halmos two projections theorem and some of its applications

Qingxiang Xu ΠνΗμΟι  (Shanghai Normal University)

15:20-16:10, March 15, 2019   Science Building A510


Halmos two projections theorem for Hilbert space operators is one of the fundamental results in operator theory. In this talk, we will focus on its generalization to the Hilbert C*-module case and its application in clarifying the Friedrichs angle between two closed submodules. Based on some new characterizations of the closed submodules and their associated projections, we will introduce a new term of isolated idempotents. Some properties of the isolated idempotents will be presented.

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