A characterization of ordinary modular eigenforms with CM
Number Theory
2025-10-28 v2
Abstract
For a rational prime we show that a -ordinary modular eigenform of weight , with -adic Galois representation , mod reductions , and with complex multiplication (CM), is characterized by the existence of -ordinary CM companion forms modulo for all integers in the sense that , where is the -adic cyclotomic character.
Keywords
Cite
@article{arxiv.1206.0177,
title = {A characterization of ordinary modular eigenforms with CM},
author = {Rajender Adibhatla and Panagiotis Tsaknias},
journal= {arXiv preprint arXiv:1206.0177},
year = {2025}
}
Comments
9 pages. Elementary proof of the main theorem added in Section 5