5 citations · 11 across the 6 of their papers we have counts for
7 papers
The block matrix representations for the quasi-projection pairs on Hilbert -modules
Xiaoyi Tian, Qingxiang Xu, Chunhong Fu
A quasi-projection pair consists of two operators and acting on a Hilbert -module , where is a projection and is an idempotent satisfying $Q^*=(2P-I)Q(2P-I)…
Characterizations of the semi-harmonious and harmonious quasi-projection pairs on Hilbert -modules
Xiaoyi Tian, Qingxiang Xu, Chunhong Fu
For each adjointable idempotent on a Hilbert -module , a specific projection called the matched projection of was introduced recently due to the characteriza…
Some aspects of semi-harmonious quasi-projection pairs
Xiaoyi Tian, Qingxiang Xu, Chunhong Fu
A term called the quasi-projection pair was introduced recently by the authors, where is a projection and is an idempotent on a Hilbert -module satisfying…
The Frobenious distances from projections to an idempotent matrix
Xiaoyi Tian, Qingxiang Xu, Chunhong Fu
For each pair of matrices and with the same order, let denote their Frobenius distance. This paper deals mainly with the Frobenius distances from projections to…
The matched projections of idempotents on Hilbert -modules
Xiaoyi Tian, Qingxiang Xu, Chunhong Fu
The aim of this paper is to give new characterizations of some fundamental issues about idempotents. In the general setting of adjointable operators on Hilbert -modules, a new…
-isomorphisms associated with two projections on a Hilbert -module
Chunhong Fu, Qingxiang Xu, Guanjie Yan
Motivated by two norm equations used to characterize the Friedrichs angle, this paper studies -isomorphisms associated with two projections by introducing the matched triple a…
Numerical radius inequalities concerning with algebraic norms
A. Zamani, M. S. Moslehian, Q. Xu +1
We give an expression for a generalized numerical radius of Hilbert space operators and then apply it to obtain upper and lower bounds for the generalized numerical radius. We also…