Displaying similar documents to “A New 'Cyclic' element Theory.”

Subnormal operators, cyclic vectors and reductivity

Béla Nagy (2013)

Studia Mathematica

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Two characterizations of the reductivity of a cyclic normal operator in Hilbert space are proved: the equality of the sets of cyclic and *-cyclic vectors, and the equality L²(μ) = P²(μ) for every measure μ equivalent to the scalar-valued spectral measure of the operator. A cyclic subnormal operator is reductive if and only if the first condition is satisfied. Several consequences are also presented.