Transfer of R-groups between p-adic inner forms of SL n

Behavior of $R$-groups for $p$-adic inner forms of quasi-split special unitary groups

‎We study $R$-groups for $p$-adic inner forms of quasi-split special unitary groups‎. ‎We prove Arthur's conjecture‎, ‎the isomorphism between the Knapp-Stein $R$-group and the Langlands-Arthur $R$-group‎, ‎for quasi-split special unitary groups and their inner forms‎. ‎Furthermore‎, ‎we investigate the invariance of the Knapp-Stein $R$-group within $L$-packets and between inner forms‎. ‎This w...

Zeros of p-adic forms

A variant of Brauer’s induction method is developed. It is shown that quartic p-adic forms with at least 9127 variables have non-trivial zeros, for every p. For odd p considerably fewer variables are needed. There are also subsidiary new results concerning quintic forms, and systems of forms.

Cross Ratios, Surface Groups, SL(n, R) and

p-adic Hurwitz groups

Herrlich showed that a Mumford curve of genus g > 1 over the p-adic complex field Cp has at most 48(g− 1), 24(g− 1), 30(g− 1) or 12(g− 1) automorphisms as p = 2, 3, 5 or p > 5. The Mumford curves attaining these bounds are uniformised by normal subgroups of finite index in certain p-adic triangle groups ∆p for p ≤ 5, or in a p-adic quadrangle group p for p > 5. The finite groups attaining these...

Maaß Cusp Forms on SL(2,R)

The present text is course material for a minicourse on Maaß cusp forms I gave at Metz University in March 2005 as a part of the Sokrates partnership activities between the universities in Metz and Paderborn. This course may be viewed as the first joint activity in the context of the new International Research Training Group " Geometry and Analysis of Symmetries " (see http://irtg.upb.de) locat...