UNIVERSAL KAROUBI CHARACTERISTIC CLASSES OF NUCLEAR C~*-ALGEBRAS

摘要

The main result of this paper is the evaluation of kernels for the Chern character and the universal Karoubi classes of nuclear C~*-algebras. It is shown that the kernel of the Chern character coincides with the subgroup of infinitely small elements of the K_0-group and the kernel of the universal Karoubi classes coincides with the subgroup of approximately scalar elements of the K_0-group.