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$C^*$-algebra structure on certain Banach algebra products

Published online by Cambridge University Press:  07 September 2020

Fatemeh Abtahi*
Affiliation:
Department of Pure Mathematics, Faculty of Mathematics and Statistics, University of Isfahan, Isfahan, Iran, 81746-73441

Abstract

Let $\mathcal A$ and $\mathcal B$ be commutative and semisimple Banach algebras and let $\theta \in \Delta (\mathcal B)$ . In this paper, we prove that $\mathcal A\times _{\theta }\mathcal B$ is a type I-BSE algebra if and only if ${\mathcal A}_e$ and $\mathcal B$ are so. As a main application of this result, we prove that $\mathcal A\times _{\theta }\mathcal B$ is isomorphic with a $C^*$ -algebra if and only if ${\mathcal A}_e$ and $\mathcal B$ are isomorphic with $C^* $ -algebras. Moreover, we derive related results for the case where $\mathcal A$ is unital.

Type
Article
Copyright
© Canadian Mathematical Society 2020

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References

Abtahi, F., Kamali, Z., and Toutounchi, M., The Bochner-Schoenberg-Eberlein property for vector-valued Lipschitz algebras. J. Math. Anal. Appl. 479(2019), 11721181. http://dx.doi.org/10.1016/j.jmaa.2019.06.073 CrossRefGoogle Scholar
Bochner, S., A theorem on Fourier-Stieltjes integrals. Bull. Amer. Math. Soc. 40(1934), 271276. http://dx.doi.org/10.1090/S0002-9904-1934-05843-9 CrossRefGoogle Scholar
Eberlein, W. F., Characterizations of Fourier-Stieltjes transforms. Duke Math. J. 22(1955), 465468.CrossRefGoogle Scholar
Inoue, J. and Takahasi, S. E., On characterizations of the image of Gelfand transform of commutative Banach algebras. Math. Nachr. 280(2007), 105126. http://dx.doi.org/10.1002/mana.200410468 CrossRefGoogle Scholar
Kamali, Z. and Lashkarizadeh Bami, M., Bochner-Schoenberg-Eberlein property for abstract Segal algebras. Proc. Jpn. Acad. Ser A. Math. Sci. 89(2013), 107110. http://dx.doi.org/10.3792/pjaa.89.107 CrossRefGoogle Scholar
Kaniuth, E., The Bochner-Schoenberg-Eberlein property and spectral synthesis for certain Banach algebra products. Canad. J. Math. 67(2015), 827847. http://dx.doi.org/10.4153/CJM-2014-028-4 CrossRefGoogle Scholar
Kaniuth, E., A course in commutative Banach algebras. Graduate Texts in Mathematics, 246, Springer, New York, 2009. http://dx.doi.org/10.1007/978-0-387-72476-8 CrossRefGoogle Scholar
Kaniuth, E., Lau, A. T., and Ülger, A., Homomorphisms of commutative Banach algebras and extensions to multiplier algebras with applications to Fourier algebras. Studia Math. 183(2007), 3562. http://dx.doi.org/10.4064/sm183-1-3 CrossRefGoogle Scholar
Kaniuth, E. and Ülger, A., The Bochner-Schoenberg-Eberlein property for commutative Banach algebras, especially Fourier and Fourier-Stieltjes algebras. Trans. Amer. Math. Soc. 362(2010), 43314356. http://dx.doi.org/10.1090/S0002-9947-10-05060-9 CrossRefGoogle Scholar
Larsen, R., An introduction to the theory of multipliers. Die Grundlehren der mathematischen Wissenchaften, 175, Springer-Verlag, New York-Heidelberg, 1971.Google Scholar
Monfared, M. S., On certain products of Banach algebras with applications to harmonic analysis. Studia Math. 178(2007), 277294. http://dx.doi.org/10.4064/sm178-3-4 CrossRefGoogle Scholar
Monfared, M. S., Character amenability of Banach algebras. Math. Proc. Camb. Philos. Soc. 144(2008), 697706. http://dx.doi.org/10.1017/S0305004108001126 CrossRefGoogle Scholar
Schoenberg, I. J., A remark on the preceding note by Bochner. Bull. Amer. Math. Soc. 40(1934), 277278. http://dx.doi.org/10.1090/S0002-9904-1934-05845-2 CrossRefGoogle Scholar
Takahasi, S. E. and Hatori, O., Commutative Banach algebras which satisfy a Bochner-Schoenberg-Eberlein-type theorem. Proc. Amer. Math. Soc. 110(1990), 149158. http://dx.doi.org/10.2307/2048254 Google Scholar
Takahasi, S. E. and Hatori, O., Commutative Banach algebras and BSE-inequalities. Math. Japonica 37(1992), 4752.Google Scholar
Ülger, A., Multipliers with closed range on commutative Banach algebras. Studia Math. 153(2002), 5980. http://dx.doi.org/10.4064/sm153-1-5 CrossRefGoogle Scholar