M. Abtahi

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20122022

most citedAn extension of Birkhoff--James orthogonality relations in semi-Hilbertian space operators

5 citations · 8 across the 6 of their papers we have counts for

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math.FA2022★ 5 cited

An extension of Birkhoff--James orthogonality relations in semi-Hilbertian space operators

S. M. Enderami, M. Abtahi, A. Zamani

Let $B (H)$ denote the $C^{*}$ -algebra of all bounded linear operators on a Hilbert space $(H, ⟨ \cdot, \cdot ⟩)$ . Given a positive…

math.FA2022

An orthogonality relation in complex normed spaces based on norm derivatives

S. M. Enderami, M. Abtahi, A. Zamani +1

Let $X$ be a complex normed space. Based on the right norm derivative $ρ_{_{+}}$ , we define a mapping $ρ_{_{\infty}}$ by \begin{equation*} ρ_{_{\infty}}(x,y) = \frac1π\int_0^{2π}e^…

math.FA2017

A Characterization of Polynomially Convex Sets in Banach Spaces

Mortaza Abtahi, Sara Farhangi

Let $E$ be a Banach space and $\X$ be the closed unit ball of the dual space $E^{*}$ . For a compact set $K$ in $E$ , we prove that $K$ is polynomially convex in $E$ if and only if the…

math.FA2016

On the character space of Banach vector-valued function algebras

Mortaza Abtahi

Given a compact space $X$ and a commutative Banach algebra $A$ , the character spaces of $A$ -valued function algebras on $X$ are investigated. The class of natural $A$ -valued functi…

math.FA2012

New characterizations of maximal ideals in algebras of continuous vector-valued functions

Mortaza Abtahi

Let X be a compact Hausdorf space, let A be a commutative unital Banach algebra, and let C(X,A) denote the algebra of continuous A-valued functions on $X$ equipped with the uniform…