Spanier-Whitehead K-Duality and Duality of Extensions of $C^{\ast }$-algebras

Ulrich Pennig, Taro Sogabe

KK-theory is a bivariant and homotopy-invariant functor on $C^{\ast }$-algebras that combines K-theory and K-homology. KK-groups form the morphisms in a triangulated category. Spanier-Wh…