Wyniki wyszukiwania

1

Character pseudo-amenability of Banach algebras

100%

Nasr-Isfahani R., Nemati M.

Colloquium Mathematicum

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2013

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tom 132

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nr 2

177-193

EN

Let 𝓐 be a Banach algebra and let ϕ be a nonzero character on 𝓐. We introduce and study a new notion of amenability for 𝓐 based on existence of a ϕ-approximate diagonal by modifying the concepts of ϕ-amenability and pseudo-amenability. We then apply these results to characterize ϕ-pseudo-amenability of various Banach algebras related to locally compact groups such as group algebras, measure algebras, certain dual algebras and Lebesgue-Fourier algebras.

2

Character contractibility of Banach algebras and homological properties of Banach modules

100%

Nasr-Isfahani R., Soltani Renani S.

Studia Mathematica

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2011

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tom 202

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nr 3

205-225

EN

Let 𝓐 be a Banach algebra and let ϕ be a nonzero character on 𝓐. We give some necessary and sufficient conditions for the left ϕ-contractibility of 𝓐 as well as several hereditary properties. We also study relations between homological properties of some Banach left 𝓐-modules, the left ϕ-contractibility and the right ϕ-amenability of 𝓐. Finally, we characterize the left character contractibility of various Banach algebras related to locally compact groups.

3

Some notions of amenability for certain products of Banach algebras

81%

Ghaderi E., Nasr-Isfahani R., Nemati M.

Colloquium Mathematicum

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2013

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tom 130

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nr 2

147-157

EN

For two Banach algebras 𝓐 and ℬ, an interesting product $𝓐 ×_{θ}ℬ$, called the θ-Lau product, was recently introduced and studied for some nonzero characters θ on ℬ. Here, we characterize some notions of amenability as approximate amenability, essential amenability, n-weak amenability and cyclic amenability between 𝓐 and ℬ and their θ-Lau product.

4

Locally convex algebras which determine a locally compact group

81%

Esslamzadeh G., Javanshiri H., Nasr-Isfahani R.

Studia Mathematica

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2016

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tom 233

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nr 3

197-207

EN

There are several algebras associated with a locally compact group 𝓖 which determine 𝓖 in the category of topological groups, such as L¹(𝓖), M(𝓖), and their second duals. In this article we add a fairly large family of locally convex algebras to this list. More precisely, we show that for two infinite locally compact groups 𝓖₁ and 𝓖₂, there are infinitely many locally convex topologies τ₁ and τ₂ on the measure algebras M(𝓖₁) and M(𝓖₂), respectively, such that (M(𝓖₁),τ₁)** is isometrically isomorphic to (M(𝓖₂),τ₂)** if and only if 𝓖₁ and 𝓖₂ are topologically isomorphic. In particular, this leads to a new proof of Ghahramani-Lau's isometrical isomorphism theorem for compact groups, different from those of Ghahramani and J. P. McClure (2006) and Dales et al. (2012).

5

Vector-valued invariant means on spaces of bounded linear maps

81%

Dashti M., Nasr-Isfahani R., Soltani Renani S.

Colloquium Mathematicum

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2013

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tom 132

|

nr 1

1-11

EN

Let 𝓐 be a Banach algebra and let ℳ be a W*-algebra. For a homomorphism Φ from 𝓐 into ℳ, we introduce and study ℳ -valued invariant Φ-means on the space of bounded linear maps from 𝓐 into ℳ. We establish several characterizations of existence of an ℳ -valued invariant Φ-mean on B(𝓐,ℳ). We also study the relation between existence of an ℳ -valued invariant Φ-mean on B(𝓐,ℳ) and amenability of 𝓐. Finally, for a character ϕ of 𝓐, we give some descriptions for ϕ-amenability of 𝓐 in terms of ℳ -valued invariant Φ-means.

Ograniczanie wyników

3 Colloquium Mathematicum

2 Studia Mathematica

5 Nasr-Isfahani R.

2 Nemati M.

2 Soltani Renani S.

1 Dashti M.

1 Esslamzadeh G.

1 Ghaderi E.

1 Javanshiri H.

1 2016

3 2013

1 2011

Character pseudo-amenability of Banach algebras

Character contractibility of Banach algebras and homological properties of Banach modules

Some notions of amenability for certain products of Banach algebras

Locally convex algebras which determine a locally compact group

Vector-valued invariant means on spaces of bounded linear maps