Paper's Title:

Weakly Compact Composition Operators on Real Lipschitz Spaces of Complex-valued Functions on Compact Metric Spaces with Lipschitz Involutions

Author(s):

D. Alimohammadi and H. Alihoseini

Department of Mathematics,
Faculty of Science, Arak University
P. O. Box,38156-8-8349, Arak,
Iran.
E-mail: d-alimohammadi@araku.ac.ir
E-mail: hr_alihoseini@yahoo.com
URL: http://www.araku.ac.ir

Abstract:

We first show that a bounded linear operator T on a real Banach space E is weakly compact if and only if the complex linear operator T on the complex Banach space E_C is weakly compact, where E_C is a suitable complexification of E and iT' is the complex linear operator on E_C associated with T. Next we show that every weakly compact composition operator on real Lipschitz spaces of complex-valued functions on compact metric spaces with Lipschitz involutions is compact.

Paper's Title:

Unital Compact Homomorphisms Between Extended Analytic Uniform Algebras

Author(s):

D. Alimohammadi and M. Mayghani

Department of Mathematics,
Faculty of Science, Arak University,
PO Box 38156-8-8349, Arak,
Iran.

d-alimohammadi@araku.ac.ir

m-maighany@yahoo.com

Abstract:

Let X and K be compact plane sets with K⊆X. We denote by A(X,K) and A(X) the algebras of all continuous complex-valued functions on X which are analytic on int(K) and int(X), respectively. It is known that A(X,K) and A(X) are natural uniform algebras on X. A(X) and A(X,K) are called analytic uniform algebra and extended analytic uniform algebra on X, respectively. In this paper we study unital homomorphisms between extended analytic uniform algebras and investigate necessary and sufficient conditions for which these homomorphisms to be compact. We also determine the spectrum of unital compact endomorphisms of extended analytic uniform algebras.

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