K. Ji

activity

20122026

2 citations · 5 across the 15 of their papers we have counts for

collaborators

16 papers

math.FA2026

Geometric operators and the third problem of Halmos

Kui Ji, Chunlan Jiang, Zhenyue Wang

In 1970, P. R. Halmos raised ten open problems on operator theory. The third problem of Halmos is the following: if an intransitive operator has an inverse, is its inverse also int…

math.FA2025

On the quasi-similarity of operators with flag structure

Xie yufang, Ji shanshan, Xu jing +1

Let $A$ denote the operator class in which every nonzero intertwiner between two operators in $A$ has dense range. Utilizing the operators in $A$ as a…

math.FA2022

The Cowen-Douglas Theory for Operator Tuples and Similarity

Kui Ji, Shanshan Ji, Hyun-Kyoung Kwon +1

We are concerned with the similarity problem for Cowen-Douglas operator tuples. The unitary equivalence counterpart was already investigated in the 1970's and geometric concepts in…

math.FA2021

A note on unitary equivalence of operators acting on reproducing kernel Hilbert spaces

Kui Ji, Shanshan Ji

A well-known theorem due to R. E. Curto and N. Salinas gives a necessary and sufficient condition for the unitary equivalence of commuting tuples of bounded linear operators acting…

math.FA2020

On the similarity of restriction of the operator to an invariant subspace

Kui Ji, Shanshan Ji, Dinesh Kumar Keshari +1

Let $M_{z}$ be the multiplication operator on the Bergman space and $M_{I}$ denote the restriction of $M_{z}$ to an invariant subspace $I$ . A question raised by K. Zhu is that when…

math.FA2019★ 2 cited

A subclass of the Cowen-Douglas class and similarity

Kui Ji, Hyun-Kyoung Kwon, Jaydeb Sarkar +1

We consider a subclass of the Cowen-Douglas class in which the problem of deciding whether two operators are similar becomes more manageable. A similarity criterion for Cowen-Dougl…

math.FA2019

Similarity Invariants of Essentially normal Cowen-Douglas Operators and Chern Polynomials

Chunlan Jiang, Kui Ji, Jinsong Wu

In this paper, we systematically study a class of essentially normal operators by using the geometry method from the Cowen-Douglas theory and prove a Brown-Douglas-Fillmore theorem…

math.FA2019

Compact operators under Orlicz functions

Ma Zhenhua, Ji Kui, Li Yucheng

In this paper, the definition of noncommutative Orlicz sequence spaces is given, these spaces generalize the Schatten classes Sp(H). After some relations of trace and norm on this…

math.FA2019

Cowen-Douglas operators and the third of Halmos' ten problems

Chunlan Jiang, Junsheng Fang, Kui Ji

Let $T$ be a bounded linear operator on a complex separable infinite dimensional Hilbert space $H$ . $T$ is called intransitive if it leaves invariant spaces other than 0…

math.FA2019

$N$ -hypercontractivity and similarity of Cowen-Douglas operators

Kui Ji, Hyun-Kyoung Kwon, Jing Xu

When the backward shift operator on a weighted space $H_{w}^{2} = {f = \sum_{j = 0}^{\infty} a_{j} z^{j} : \sum_{j = 0}^{\infty} ∣ a_{j} ∣^{2} w_{j} < \infty}$ is an $n$ -hypercontraction, we prove that t…

math.FA2019

Geometric Similarity invariants of Cowen-Douglas Operators

Chunlan Jiang, Kui Ji, Dinesh Kumar Keshari

In 1978, M. J. Cowen and R.G. Douglas introduce a class of operators (known as Cowen-Douglas class of operators) and associates a Hermitian holomorphic vector bundle to such an ope…

math.FA2014

Curvature and the Second fundamental form in classifying quasi-homogeneous holomorphic curves and operators in the Cowen-Douglas class

Chunlan Jiang, Kui Ji, Gadadhar Misra

In this paper we study quasi-homogeneous operators, which include the homogeneous operators, in the Cowen-Douglas class. We give two separate theorems describing canonical models (…

math.FA2014★ 1 cited

Rigidity of the flag structure for a class of Cowen-Douglas operators

Kui Ji, Chunlan Jiang, Dinesh Kumar Keshari +1

The explicit description of irreducible homogeneous operators in the Cowen-Douglas class and the localization of Hilbert modules naturally leads to the definition of a smaller clas…

math.FA2014

Flag structure for operators in the Cowen-Douglas class

Kui Ji, Chunlan Jiang, Dinesh Kumar Keshari +1

The explicit description of homogeneous operators and localization of a Hilbert module naturally leads to the definition of a class of Cowen-Douglas operators possessing a flag str…

math.OA2014

Curvature formulas of holomorphic curves on $C^{*}$ -algebras and Cowen-Douglas Operators

Kui Ji

For $Ω \subseteq C$ a connected open set, and $U$ a unital $C^{*}$ -algebra, let $I (U)$ and $P (U)$ denote the sets of a…

math.FA2012★ 2 cited

Similarity of Quotient Hilbert modules in the Cowen-Douglas Class

Kui Ji, Jaydeb Sarkar

In this paper, we consider the similarity and quasi-affinity problems for Hilbert modules in the Cowen-Douglas class associated with the complex geometric objects, the hermitian an…

Geometric operators and the third problem of Halmos

On the quasi-similarity of operators with flag structure

The Cowen-Douglas Theory for Operator Tuples and Similarity

A note on unitary equivalence of operators acting on reproducing kernel Hilbert spaces

On the similarity of restriction of the operator to an invariant subspace

A subclass of the Cowen-Douglas class and similarity

Similarity Invariants of Essentially normal Cowen-Douglas Operators and Chern Polynomials

Compact operators under Orlicz functions

Cowen-Douglas operators and the third of Halmos' ten problems

N-hypercontractivity and similarity of Cowen-Douglas operators

Geometric Similarity invariants of Cowen-Douglas Operators

Curvature and the Second fundamental form in classifying quasi-homogeneous holomorphic curves and operators in the Cowen-Douglas class

Rigidity of the flag structure for a class of Cowen-Douglas operators

Flag structure for operators in the Cowen-Douglas class

Curvature formulas of holomorphic curves on C∗-algebras and Cowen-Douglas Operators

Similarity of Quotient Hilbert modules in the Cowen-Douglas Class

$N$ -hypercontractivity and similarity of Cowen-Douglas operators

Curvature formulas of holomorphic curves on $C^{*}$ -algebras and Cowen-Douglas Operators