Kalpesh J. Haria

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20112026

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6 papers · 1 filter

math.FA2026

Regularity of the Sz.-Nagy and Foiaş Factorization of Characteristic Functions and Its Multivariable Analogue

Kalpesh J. Haria, Aashish Kumar Maurya

Given a contraction with an invariant subspace and a row contraction with a joint invariant subspace, a factorization of their characteristic functions was obtained by Sz.-Nagy and…

math.FA2026

$k$ -Regular Factorizations and Joint Invariant Subspaces of Completely Non-Coisometric Row Contractions

Kalpesh J. Haria, Aashish Kumar Maurya

This article investigates $k$ -regular factorizations of characteristic functions associated with completely non-coisometric row contractions. In this setting, a one-to-one correspo…

math.FA2023

Characteristic Functions and Colligations

Neeru Bala, Santanu Dey, Kalpesh J. Haria +1

The characteristic function of row contractions and the characteristic function of liftings of row contractions are multi-analytic operators which are complete invariants up to uni…

math.FA2020

Commuting row contractions with polynomial characteristic functions

Monojit Bhattacharjee, Kalpesh J. Haria, Jaydeb Sarkar

A characteristic function is a special operator-valued analytic function defined on the open unit ball of $C^{n}$ associated with an $n$ -tuple of commuting row contraction o…

math.FA2017

Isometric dilations and von Neumann inequality for a class of tuples in the polydisc

Sibaprasad Barik, B. Krishna Das, Kalpesh J. Haria +1

The celebrated Sz.-Nagy and Foias and Ando theorems state that a single contraction, or a pair of commuting contractions, acting on a Hilbert space always possesses isometric dilat…

math.FA2016

Factorizations of Characteristic Functions

Kalpesh J. Haria, Amit Maji, Jaydeb Sarkar

Let $A = (A_{1}, \dots, A_{n})$ and $B = (B_{1}, \dots, B_{n})$ be row contractions on $H_{1}$ and $H_{2}$ , respectively, and $X$ be a row operator from $\oplus_{i=1}^n \…