A function algebra without any point derivation. (English) Zbl 0628.46055

Jarosz, Krzysztof; Sawoń, Zbigniew

Čas. Pěstování Mat. 111, 230-234 (1986).

The authors construct a commutative Banach algebra A with unit such that \(\| f^ 2\| =\| f\|^ 2\) holds for any \(f\in A\) and with the following two properties:
(1) A admits no non-zero derivation at any point of the maximal ideal space M(A) of A.
(2) The Shilov boundary of A is a proper subset of M(A).
This answers a question posed by J. Wermer [J. Funct. Anal. 1, 28- 36 (1967; Zbl 0159.421)].

Reviewer: M.von Renteln

MSC:

46J10	Banach algebras of continuous functions, function algebras
46J20	Ideals, maximal ideals, boundaries
47B47	Commutators, derivations, elementary operators, etc.

Keywords:

function algebra without any point derivation; maximal ideal space; Shilov boundary

Citations:

Zbl 0159.421