Arthur Bartels
He is concerned with topology , including the Farrell–Jones conjecture about the algebraic structure of the K-theory and L-theory of group rings , which he proved in special cases with colleagues; specifically , he proved the case of mapping class groups with Mladen Bestvina and the cases of hyperbolic groups and CAT ( 0 ) -groups with Wolfgang Lück and Holger Reich . 
<triplet> L-theory <subj> K-theory <obj> part of