Reflexive Ideals in Iwasawa Algebras
arXiv:0710.0624
Abstract
Let be a torsionfree compact -adic analytic group. We give sufficient conditions on and which ensure that the Iwasawa algebra of has no non-trivial two-sided reflexive ideals. Consequently, these conditions imply that every nonzero normal element in is a unit. We show that these conditions hold in the case when is an open subgroup of $\SL_2(\Zp)$ and is arbitrary. Using a previous result of the first author, we show that there are only two prime ideals in when is a congruence subgroup of $\SL_2(\Zp)$: the zero ideal and the unique maximal ideal. These statements partially answer some questions asked by the first author and Brown.