Laurian Suciu

activity

20182020

collaborators

4 papers

math.FA2020

High order isometric liftings and dilations

Catalin Badea, Vladimir Müller, Laurian Suciu

We show that a Hilbert space bounded linear operator has an $m$ -isometric lifting for some integer $m \geq 1$ if and only if the norms of its powers grow polynomially. In analogy wit…

math.FA2019

Hilbert space operators with two-isometric dilations

Catalin Badea, Laurian Suciu

A bounded linear Hilbert space operator $S$ is said to be a $2$ -isometry if the operator $S$ and its adjoint $S^{*}$ satisfy the relation $S^{* 2} S^{2} - 2 S^{*} S + I = 0$ . In this pa…

math.FA2018

The Cauchy dual and 2-isometric liftings of concave operators

Catalin Badea, Laurian Suciu

We present some 2-isometric lifting and extension results for Hilbert space concave operators. For a special class of concave operators we study their Cauchy dual operators and dis…

math.FA2018

Similarity problems, Folner sets and isometric representations of amenable semigroups

Catalin Badea, Laurian Suciu

We revisit Sz.-Nagy's criteria for similarity of Hilbert space bounded linear operators to isometries or unitaries and present new ones. We also discuss counterparts of the Dixmier…