6 papers · 1 filter
Inner and characteristic functions in polydiscs
Ramlal Debnath, Deepak K. Pradhan, Jaydeb Sarkar
Characteristic functions of linear operators are analytic functions that serve as complete unitary invariants. Such functions, as long as they are built in a natural and canonical…
Two problems on submodules of
Ramlal Debnath, Srijan Sarkar
Given any shift-invariant closed subspace (aka submodule) of the Hardy space over the unit polydisc (where ), let $R_{z_j}:=M_{z_j}|_{\m…
Pairs of inner projections and two applications
Ramlal Debnath, Deepak K. Pradhan, Jaydeb Sarkar
Orthogonal projections onto closed subspaces of of the form for inner functions on are referred to as inner projections,…
$\clw$-hypercontractions and their model
Monojit Bhattacharjee, B. Krishna Das, Ramlal Debnath +1
We revisit the study of -hypercontractions corresponding to a single weight sequence introduced by Olofsson in \cite{O} and find an analogue of Nagy-Foias c…
Beurling quotient modules on the polydisc
Monojit Bhattacharjee, B. Krishna Das, Ramlal Debnath +1
Let denote the Hardy space over the polydisc , . A closed subspace is called Beurling quotient…
Factorizations of Schur functions
Ramlal Debnath, Jaydeb Sarkar
The Schur class, denoted by , is the set of all functions analytic and bounded by one in modulus in the open unit disc in the complex plane $\…