In this paper, we introduce the concept of normality of ad-tuple of bounded linear operators
acting on a complex Hilbert space H when an additional semi-inner product induced by a …

We study jointly quasinormal and spherically quasinormal pairs of commuting operators on
Hilbert space, as well as their powers. We first prove that, up to a constant multiple, the only …

Abstract In a recent paper [11], RE Curto, SH Lee and J. Yoon asked the following question.
Let A be a subnormal operator, and assume that A 2 is quasinormal. Does it follow that A is …

We introduce two natural notions of multivariable Aluthge transforms (toral and spherical),
and study their basic properties. In the case of 2-variable weighted shifts, we first prove that …

We study Euclidean operator radius inequalities of d-tuple operators as well as the sum and
the product of d-tuple operators. A power inequality for the Euclidean operator radius of d …

In this paper we aim to study the tensor product and the tensor sum of two jointly-normal
operators. Mainly, an alternative proof is given for the result of Chō and Takaguchi (Pac J …

For 2-variable weighted shifts W (α, β)≡(T1, T2) we study the invariance of (joint) k-
hyponormality under the action (h,ℓ)↦W_(α,β)^(h,ℓ):=(T_1^h,T_2^ℓ)(h,ℓ≥1). We show that …

In this paper we give a new proof of the existence of disintegration measures using the
Hausdorff Moment Problem on a Borel measurable space X× Y, where X≡ Y is the unit …

Joint n-normality of linear transformations Page 1 J. Math. Computer Sci., 25 (2022), 361–369
Online: ISSN 2008-949X Journal Homepage: www.isr-publications.com/jmcs Joint n-normality …

In this note, we get the Berger measure of the weighted shift S (a, b, c, d) with weights α n:= a
n+ bc n+ d (a, b, c, d> 0 and n⩾ 0) as well as its p-subshift. Then we will give examples from …