ISSN : 1226-0657
Let T be a bounded linear operator on a complex Hilbert space H. For a positive integer k, an operator T is said to be a k-quasi-2-isometric operator if T<sup>∗k</sup>(T<sup>∗2</sup>T<sup>2</sup> − 2T<sup>∗</sup>T + I)T<sup>k</sup> = 0, which is a generalization of 2-isometric operator. In this paper, we consider basic structural properties of k-quasi-2-isometric operators. Moreover, we give some examples of k-quasi-2-isometric operators. Finally, we prove that generalized Weyl’s theorem holds for polynomially k-quasi-2-isometric operators.
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