Exposed points in the set of representing measures for the disc algebra
Volume 61 / 1995
Annales Polonici Mathematici 61 (1995), 59-62
DOI: 10.4064/ap-61-1-59-62
Abstract
It is shown that for each nonzero point x in the open unit disc D, there is a measure whose support is exactly ∂D ∪ {x} and that is also a weak*-exposed point in the set of representing measures for the origin on the disc algebra. This yields a negative answer to a question raised by John Ryff.
