Norm conditions for real-algebra isomorphisms between uniform algebras

Central European Journal of Mathematics - Tập 8 - Trang 135-147 - 2010
Rumi Shindo1
1Department of Mathematical Science, Graduate School of Science and Technology, Niigata University, Niigata, Japan

Tóm tắt

Let A and B be uniform algebras. Suppose that α ≠ 0 and A 1 ⊂ A. Let ρ, τ: A 1 → A and S, T: A 1 → B be mappings. Suppose that ρ(A 1), τ(A 1) and S(A 1), T(A 1) are closed under multiplications and contain expA and expB, respectively. If ‖S(f)T(g) − α‖∞ = ‖ρ(f)τ(g) − α‖∞ for all f, g ∈ A 1, S(e 1)−1 ∈ S(A 1) and S(e 1) ∈ T(A 1) for some e 1 ∈ A 1 with ρ(e 1) = 1, then there exists a real-algebra isomorphism $$ \tilde S $$ : A → B such that $$ \tilde S $$ (ρ(f)) = S(e 1)−1 S(f) for every f ∈ A 1. We also give some applications of this result.

Tài liệu tham khảo

Browder A., Introduction to function algebras, W.A. Benjamin, 1969 Hatori O., Miura T., Takagi H., Characterizations of isometric isomorphisms between uniform algebras via nonlinear range-preserving property, Proc. Amer. Math. Soc., 2006, 134, 2923–2930 Hatori O., Miura T., Takagi H., Unital and multiplicatively spectrum-preserving surjections between semi-simple commutative Banach algebras are linear and multiplicative, J. Math. Anal. Appl., 2007, 326, 281–296 Hatori O., Miura T., Takagi H., Multiplicatively spectrum-preserving and norm-preserving maps between invertible groups of commutative Banach algebras, preprint. Hatori O., Hino K., Miura T., Oka H., Peripherally monomial-preserving maps between uniform algebras, Mediterr. J. Math., 2009, 6, 47–59 Hatori O., Miura T., Shindo R., Takagi H., Generalizations of spectrally multiplicative surjections between uniform algebras, preprint Honma D., Surjections on the algebras of continuous functions which preserve peripheral spectrum, Contemp. Math., 2006,435, 199–205 Honma D., Norm-preserving surjections on algebras of continuous functions, Rocky Mountain J. Math., to appear Kelley J.L., General topology, D. Van Nostrand Company (Canada), 1955 Lambert S., Luttman A., Tonev T., Weakly peripherally-multiplicative mappings between uniform algebras, Contemp. Math., 2007, 435, 265–281 Luttman A., Tonev T., Uniform algebra isomorphisms and peripheral multiplicativity, Proc. Amer. Math. Soc., 2007, 135, 3589–3598 Luttman A., Lambert S., Norm conditions for uniform algebra isomorphisms, Cent. Eur. J. Math., 2008, 6(2), 272–280 Miura T., Honma D., Shindo R., Divisibly norm-preserving maps between commutative Banach algebras, Rocky Mountain J. Math., to appear Molnár L., Some characterizations of the automorphisms of B(H) and C(X), Proc. Amer. Math. Soc., 2001, 130, 111–120 Rao N.V., Roy A.K., Multiplicatively spectrum-preserving maps of function algebras, Proc. Amer. Math. Soc., 2005, 133, 1135–1142 Rao N.V., Roy A.K., Multiplicatively spectrum-preserving maps of function algebras II, Proc. Edinburgh Math. Soc., 2005, 48,219–229 Shindo R., Maps between uniform algebras preserving norms of rational functions, preprint