activity
20242026
collaborators

5 papers

math.FA2026

Lower and upper bounds of joint -numerical radius functions

Zameddin I. Ismailov, Sergei Silvestrov, Pembe Ipek Al

In this study, the classical results on the joint numerical radius for -tuples of Hilbert space operators are extended to the setting of the joint -numerical radius. New…

math.FA2026

Some Spectral Problems for First Order Normal Differential Operators in the Weighted Hilbert Spaces of Vector-Functions

Zameddin I. Ismailov, Pembe Ipek Al, Mohammad Sababheh

In this article, in order to the minimal operator generated by the first-order differential-operator expression in the weighted Hilbert space of vector functions in the finite inte…

math.FA2026

A new collection of tuple operator inequalities

Zameddin I. Ismailov, Pembe Ipek Al, Hamid Reza Moradi +1

In this paper, we present several new bounds for the norm and numerical radius of sums of Hilbert space operators. The obtained bounds form a new collection that enriches our under…

math.FA2025

Some spectral properties and convergence of the -numerical radius and -Crawford number

Pembe Ipek Al, Zameddin I. Ismailov, Fuad Kittaneh +1

In this study, some estimates are given for the -numerical radius and -Crawford number via the -numerical radius and -Crawford number for the -bounded…

math.FA2024

Generalizations of the Numerical Radius, Crawford Number and Numerical Index Functions in the Weighted Case

Zameddin I. Ismailov, Pembe Ipek Al

In this article, firstly, some simple and smoothness properties of the weighted numerical radius and the weighted Crawford number functions are investigated. Then, some generalizat…