3 papers
math.FA2019
Toeplitz operators and pseudo-extensions
Tirthankar Bhattacharyya, B. Krishna Das, Haripada Sau
There are three main results in this paper. First, we find an easily computable and simple condition which is necessary and sufficient for a commuting tuple of contractions to poss…
math.FA2015
Inner multipliers and Rudin type invariant subspaces
Arup Chattopadhyay, B. Krishna Das, Jaydeb Sarkar
Let be a Hilbert space and be the -valued Hardy space over the unit disc in . The well known Beu…
math.FA2012
The Defect Sequence for Contractive Tuples
Tirthankar Bhattacharyya, Bata Krishna Das, Santanu Sarkar
We introduce the defect sequence for a contractive tuple of Hilbert space operators and investigate its properties. The defect sequence is a sequence of numbers, called defect dime…