We prove Rapoport's dimension conjecture for affine Deligne-Lusztig varieties
for GL_h and superbasic b. From this case the general dimension formula for
affine Deligne-Lusztig varieties for special maximal compact subgroups of split
groups follows, as was shown in a recent paper by Goertz, Haines, Kottwitz, and
Reuman.Comment: 13 pages, some small mistakes corrected, author's last name changed
from Mierendorff to Viehman
