17 citations · 44 across the 22 of their papers we have counts for
7 papers · 1 filter
Expansive operators which are power bounded or algebraic
B. P. Duggal, I. H. Kim
Given Hilbert space operators invertible, is expansive (resp., isometric) for some positive integer if $\triangle_{T^*,T}^m(P)=\su…
Operator roots of polynomials:iso-symmetric operators
B. P. Duggal, I. H. Kim
Given Hilbert space operators , , and such that commutes with and commutes with , and integers , we say that the pairs of op…
Asymptotic limits, Banach limits, and Cesàro means
C. S. Kubrusly, B. P. Duggal
Every new inner product in a Hilbert space is obtained from the original one by means of a unique positive operator The first part of the paper is a survey on applications of su…
Drazin invertible -expansive operators
B. P. Duggal, I. H. Kim
A Hilbert space operator is -expansive, for some positive integer and operator , if $\sum_{j=0}^m{(-1)^j\left(\begin{array}{clcr}m\\j\end{array}\right)T…
Structure of -quasi left -invertible and related classes of operators
B. P. Duggal, I. H. Kim
Given Hilbert space operators $T, S\in\B$, let and $δ\in B(\B)$ denote the elementary operators and $δ_{T,S}(X)=(L_T-R_S)(X)=TX…
Structure of elementary operators defining -left invertible, -selfadjoint and related classes of operators
B. P. Duggal, I. H. Kim
We use elementary algebraic properties of left, right multiplication operators to prove some deep structural properties of left -invertible, -isometric, -selfadjoint and o…
Left m-invertibility by the adjoint of Drazin inverse and m-selfadjointness of Hilbert space operators
B. P. Duggal, I. H. Kim
A Hilbert space operator $A\in\B$ is left -invertible by $B\in\B$ (resp., $B\in\B$ is an -adjoint of $A\in\B$) for some operator $X\in\B$ if $\triangle_{B,A}^m(X)=\su…