“…potential) the existence of absolutely continuous spectrum at low disorder has only been shown for trees and treelike graphs 1 of infinite dimension with exponentially growing boundary. A lot of work has been done in extending Klein's original result, also in recent years, [ASW,AW1,AW2,FHS1,FHS2,FHS3,FHH,Ha,KLW,KlS,Sa,Sh]. At large disorder and on the edge of the spectrum one typically finds Anderson localization (pure point spectrum) in any dimension [A, AM, CKM, DK, DLS, FMSS, FS, Klo, W].…”