Penn Arts & Sciences Logo

Penn Mathematics Colloquium

Wednesday, April 13, 2011 - 4:30pm

Victor Lomonosov

Kent State University

Location

University of Pennsylvania

DRL 4C6

The Bishop-Phelps Theorem asserts that the set of functionals which attain the maximum value on a closed bounded convex subset of a real Banach space is norm dense in the dual space. We show that this statement cannot be extended to general complex Banach spaces by constructing a closed bounded convex set with no support points. We also show that if the Bishop-Phelps Theorem is correct for a uniform dual algebra R of operators in a Hilbert space, then the algebra R is selfadjoint.