Lg. Brown et Nc. Wong, On C*-algebras cut down by closed projections: Characterizing elements viathe extreme boundary, TAIWAN J M, 5(2), 2001, pp. 433-441
Let A be a C*-algebra. Let z be the maximal atomic projection and p a close
d projection in A**. It is known that x in A** has a continuous atomic part
, i.e., zx = za for some a in A, whenever x is uniformly continuous on the
set of pure states of A. Under some additional conditions, we shall show th
at if x is uniformly continuous on the set of pure states of A supported by
p, or its weak* closure, then pxp has a continuous atomic part, i.e., zpxp
= zpap for some a in A.