Integrality in the Steinberg module and the top-dimensional cohomology of SLn OK
Integrality in the Steinberg module and the top-dimensional cohomology of SLn OK
We prove a new structural result for the spherical Tits building attached to SL_n(K) for many number fields K, and more generally for the fraction fields of many Dedekind domains O: the Steinberg module St_n(K) is generated by integral apartments if and only if the ideal class group cl(O) is …