4 papers
On inequalities involving the spherical operator transforms
Fuad Kittaneh, Satyajit Sahoo, Hranislav Stanković
This paper explores refinements of some operator norm inequalities through the generalized spherical Aluthge transform and the spherical Heinz transform. We introduce the spherical…
Birkhoff-James orthogonality: A Minimax Theorem approach
Hranislav Stanković
In this paper, we present an elementary proof of the Bhatia-Šemrl Theorem, utilizing the Minimax Theorem for bounded linear operators by Asplund and Ptak [1]. Some related results…
Characterizations of positive operators via their powers
Hranislav Stanković
In this paper, we present new characterizations of normal and positive operators in terms of their powers. Among other things, we show that if is normal, $\mathcal{W}(T^{2k+1…
-numerical radius of rank-one operators and the generalized Buzano inequality
Dušan Denčić, Hranislav Stanković, Mihailo Krstić +1
Here, we study the -numerical radius of rank-one operators on a Hilbert space . More precisely, for and , we establish the formu…