discipline

Mathematics

subject

Operator extensions

lecturers

Zoltán Sebestyén

credits

2

period

1., 2., 3., 4.

curriculum

Hilbert space operators defined only on a subspace called after Halmos suboperators. Characterization of subpositive suboperators are the key result. Subsymmetric suboperators are given as a corollary. Krein’s theory of subsymmetric contractions are generalised. Subsymmetric and compact operator extension is a given as the arithmetic mean of the smallest and largest normpreserving such extensions. Subsymmetric unitary operators are characterized as symmetric isometries. Applications to dilation theory are also given.

literature

-

form of tuition

Lectures

mode of assessment

oral exam