O. S. Cyprian

On Relation between the Joint Essential Spectrum and the Joint Essential Numerical Range of Aluthge Transform

O. S. Cyprian · Journal of Advances in Mathematics and Computer Science · 2021

Associated with every commuting m-tuples of operators on a complex Hilbert space X is its Aluthge transform. In this paper we show that every commuting m-tuples of operators on a complex Hilbert space X and its Aluthge transform have the same joint essential spectrum. Further, it...

Open access Research Article 10.9734/jamcs/2021/v36i830386

Results on the Joint Essential Maximal Numerical Ranges

O. S. Cyprian · Journal of Advances in Mathematics and Computer Science · 2020

In the present paper, we show the equivalent denitions of the joint essential maximal numerical range. In the current paper, we show that the properties of the classical numerical range such as compactness also hold for the joint essential maximal numerical range. Further, we sho...

Open access Research Article 10.9734/jamcs/2020/v35i330255

Certain Properties Involving the Joint Essential Numerical Ranges

O. S. Cyprian · Asian Research Journal of Mathematics · 2020

The concept of essential numerical range of an operator was dened and studied by Stamp i and Williams in 1972. Researchers generalised this idea of essential numerical range to a group of operators to the joint essential numerical range. In this paper, we consider the jointessent...

Open access Research Article 10.9734/arjom/2020/v16i330176