Susmita Das

activity

20212023

collaborators

3 papers

math.FA2023

Completely non unitary contractions and Analyticity

Susmita Das

We study completely non-unitary contractions $T$ with finite dimensional defect spaces $D_{T}$ and $D_{T^{*}}$ . We present a complete classification of all such con…

math.FA2022

Left-invertibility of rank-one perturbations

Susmita Das, Jaydeb Sarkar

For each isometry $V$ acting on some Hilbert space and a pair of vectors $f$ and $g$ in the same Hilbert space, we associate a nonnegative number $c (V; f, g)$ defined by \[ c(V; f,g)…

math.FA2021

Invariant subspaces of analytic perturbations

Susmita Das, Jaydeb Sarkar

By analytic perturbations, we refer to shifts that are finite rank perturbations of the form $M_{z} + F$ , where $M_{z}$ is the unilateral shift and $F$ is a finite rank operator on the…