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M. Eshaghi Gordji

Publications and source records attributed to M. Eshaghi Gordji.

45 records · Page 3Linked to original sources

n-Jordan homomorphisms

Let $n\in \Bbb N,$ and let $A,B$ be two rings. An additive map $h: A\to B$ is called n-Jordan homomorphism if $h(a^n)=(h(a))^n$ for all $a \in {A}$. Every Jordan homomorphism is an n-Jordan homomorphism, for all $n\geq 2,$ but the converse is false, in general. In this paper we investigate the n-Jordan homomorphisms on Banach algebras. Indeed some results related to continuity are given as well.

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The fourth duals of Banach algebras

Let $\cal A$ be a Banach algebra. Then $\cal A^{**}$ the second dual of $\cal A$ is a Banach algebra with first (second) Arens product. We study the Arens products of $\cal A^{4}(=({\cal A^{**}})^{**}).$ We found some conditions on $\cal A^{**}$ to be a left ideal in $\cal A^{4}.$ We found the biggest two sided ideal $I$ of ${\cal A},$ in which $I$ is a left (right) ideal of ${\cal A}^{**}$.

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Module extensions of dual Banach algebras

In this paper we define the module extension dual Banach algebras and we use this Banach algebras to finding the relationship between $weak^*-$continuous homomorphisms of dual Banach algebras and Connes-amenability. So we study the $weak^*-$continuous derivations on module extension dual Banach algebras.

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Left introverted subspaces of duals of Banach algebras and $WEAK^*-$continuous derivations on dual Banach algebras

Let $X$ be a left introverted subspace of dual of a Banach algebra. We study $Z_t(X^*),$ the topological center of Banach algebra $X^*$. We fined the topological center of $(X\cA)^*$, when $\cA$ has a bounded right approximate identity and $\cA\subseteq X^*.$ So we introduce a new notation of amenability for a dual Banach algebra $\cal A$. A dual Banach algebra $\cal A$ is weakly Connes-amenable if the first $weak^*-$continuous cohomology group of $\cal A$ with coefficients in $\cal A$ is zero; i.e., $H^1_{w^*}(\cal A, \cal A)=\{o\}$. We study the weak Connes-amenability of some dual Banach algebras.

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First cohomology on weighted semigroup algebras

The aim of this work is to generalize Johnson's techniques in order to apply them to establish a bijective correspondence between $S$-derivations and continuous derivations on $M_a(S,ω),$ where $S$ is a locally compact foundation semigroup with identity $e$, and $ω$ is a weight function on $S$, and apply it to find a necessary condition for amenability of weighted group algebras.

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Derivations into duals of closed ideals of Banach algebras

Let $\cal A$ be a Banach algebra. We study those closed ideals $I$ of $\cal A$ for which the first cohomology group of $\cal A$ with coefficients in $I^*$ is trivial; i.e. $H^1(\cal A,I^*)=\{0\}$. We investigate such closed ideals when $\cal A$ is weakly amenable or biflat. Also we give some hereditary properties of ideal amenability.

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Derivations into n-th duals of ideals of Banach algebras

We introduce two notions of amenability for a Banach algebra $\cal A$. Let $n\in \Bbb N$ and let $I$ be a closed two-sided ideal in $\cal A$, $\cal A$ is $n-I-$weakly amenable if the first cohomology group of $\cal A$ with coefficients in the n-th dual space $I^{(n)}$ is zero; i.e., $H^1({\cal A},I^{(n)})=\{0\}$. Further, $\cal A$ is n-ideally amenable if $\cal A$ is $n-I-$weakly amenable for every closed two-sided ideal $I$ in $\cal A$. We find some relationships of $n-I-$ weak amenability and $m-J-$ weak amenability for some different m and n or for different closed ideals $I$ and $J$ of $\cal A$.

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Connes amenability of the second dual of Arens regular Banach algebras

In this paper we study the Connes amenability of the second dual of Arens regular Banach algebras. Of course we provide a partial answer to the question posed by Volker Runde. Also we fined the necessary and sufficient conditions for the second dual of an Arens regular module extension Banach algebra to be Connes amenable when the module is reflexive.

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