Papers by fatemeh golfarshchi
Communications in Mathematical Analysis, 2020
Let A and B be two unital C * -algebras and φ : A → B be a linear map. In this paper, we investig... more Let A and B be two unital C * -algebras and φ : A → B be a linear map. In this paper, we investigate the structure of linear maps between two C * -algebras that preserve a certain property or relation. In particular, we show that if φ is unital, B is commutative and
Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical radius pres... more Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical radius preserving linear map from A into B. We discuss a Nagasawa type theorem for this maps and show that ϕ is a Jordan isomorphism, if A and B are commutative.
Journal of Mathematics and Computer Science, 2013
Let A and B be unital semi-simple Banach algebras. If B is a liminal C*-algebra and φ is a surjec... more Let A and B be unital semi-simple Banach algebras. If B is a liminal C*-algebra and φ is a surjective spectrum preserving linear mapping from A to B, then φ is a Jordan homomorphism.
Abstract: Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical r... more Abstract: Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical radius preserving linear map from A into B. We discuss a Nagasawa type theorem for this maps and show that ϕ is a Jordan isomorphism, if A and B are commutative.
Numerical range preserving linear maps is a very important concept and is studied by many authors... more Numerical range preserving linear maps is a very important concept and is studied by many authors. In this paper we study numerical range compressing linear maps and show that every numerical range compressing linear map between two unital commutative C∗-algebras is a unital ∗-homomorphism.
Communications in Mathematical Analysis, 2018
Let $A$ be a unital $C^{*}$-algebra which has a faithful state. If $varphi:Arightarrow A$ is a un... more Let $A$ be a unital $C^{*}$-algebra which has a faithful state. If $varphi:Arightarrow A$ is a unital linear map which is bijective and invertibility preserving or surjective and spectral radius preserving, then $varphi$ is a Jordan isomorphism. Also, we discuss other types of linear preserver maps on $A$.
Communications in Mathematical Analysis, 2020
Let $A$ and $B$ be two unital $C^{*}$-algebras and $varphi:A rightarrow B$ be a linear map. In th... more Let $A$ and $B$ be two unital $C^{*}$-algebras and $varphi:A rightarrow B$ be a linear map. In this paper, we investigate the structure of linear maps between two $C^{*}$-algebras that preserve a certain property or relation. In particular, we show that if $varphi$ is unital, $B$ is commutative and $V(varphi(a)^{*}varphi(b))subseteq V(a^{*}b)$ for all $a,bin A$, then $varphi$ is a $*$-homomorphism. It is also shown that if $varphi(|ab|)=|varphi(a)varphi(b)|$ for all $a,bin A$, then $varphi$ is a unital $*$-homomorphism.
International Journal of Pure and Apllied Mathematics, 2013
Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical radius pres... more Let A and B be unital complex Banach algebras, and ϕ be a unital surjective numerical radius preserving linear map from A into B. We discuss a Nagasawa type theorem for this maps and show that ϕ is a Jordan isomorphism, if A and B are commutative.
Let A and B be unital complex Banach algebras, and ' be a unital surjective numerical radius ... more Let A and B be unital complex Banach algebras, and ' be a unital surjective numerical radius preserving linear map from A into B. We discuss a Nagasawa type theorem for this maps and show that ' is a Jordan isomorphism, if A and B are commutative.
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Papers by fatemeh golfarshchi