Triviality of the Hecke action on ordinary Drinfeld cuspforms of level ${\Gamma }_1(t^n)$

Abstract

Let $k\ge 2$ and $n\ge 1$ be any integers. In this paper, we prove that all Hecke operators act trivially on the space of ordinary Drinfeld cuspforms of level ${\Gamma }_1(t^n)$ and weight $k$.

arXiv comment21 pages; Proposition 2.6 and related things have been removed due to a gap in the proof of the proposition