6 citations · 10 across the 7 of their papers we have counts for
15 papers · 1 filter
Forms of biisometric operators and biorthogonality
B. P. Duggal, C. S. Kubrusly
The paper proves two results involving a pair (A,B) of P-biisometric or (m,P)-biisometric Hilbert-space operators for arbitrary positive integer m and positive operator P. It is sh…
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…