The universal property of graded $K{K}^G$-theory

Bernhard Burgstaller

To each Kasparov cycle $z$ we attach inclusions $B\stackrel{j_z}{\to }{Y}_z\stackrel{i_z}{\to }{X}_z$ satisfying $[z]j_z{i}_z=s_z{i}_z$. A lift of a second factor along $k_z=j_z{i}_z$ therefore re…