Full paper in PDF:
$% J. Gómez and J. L. G. Llavona, Multiplicative functionals on function algebras, Rev. Mat. Univ. Complut. Madrid 1 (1988), no. 1, 2, 3, 19–22.%$

Multiplicative Functionals on Function Algebras

Javier GÓMEZ and José L. G. LlAVONA
Departamento de Análisis Matemático
Facultad de CC. Matemáticas
Universidad Complutense
28040 Madrid Spain
 

Received: February 12, 1988
ABSTRACT

Let X  be a completely regular Hausdorff space and C(X)  the algebra of all continuous K  -valued functions on X  (K= R  or C  ). If A  (_  C(X)  is a subalgebra, in Michael (1952) can be found conditions on A  under which each character of A  , i.e., each non-zero K  -linear multiplicative functional f :A-->  K  , is given by a point evaluation at some point of X  .

In this paper we present a “Michael” type theorem for the particular case in which X  is a real Banach space. As a consequence it is showed that if E  is a separable Banach space or E  is the topological dual space of a separable Banach space and A  is the algebra of all real analytic or the algebra of all real Cm  -functions, m = 0,1,..., oo  , on E  , then every character f  of A  is a point evaluation at some point of E  .

1980 Mathematics Subject Classification (1985 revision): 46B25.