English

Explicit Methods for Hilbert Modular Forms of Weight 1

Number Theory 2020-02-28 v2

Abstract

In this article we present an algorithm that uses the graded algebra structure of Hilbert modular forms to compute the adelic qq-expansion of Hilbert modular forms of weight one as the quotient of Hilbert modular forms of higher weight. The main improvement to existing methods is that our algorithm can be applied in weight 11, which fills a gap left by standard computational methods. Additionally, the algorithm can be used to compute Hilbert modular forms over finite fields in all characteristic simultaneously. We use this algorithm to compute a first candidate of a Hilbert modular form of parallel weight 11 that is non-liftable and specify the exact conditions under which our candidate qq-expansion corresponds to a non-liftable Hilbert Modular form.

Keywords

Cite

@article{arxiv.1710.02287,
  title  = {Explicit Methods for Hilbert Modular Forms of Weight 1},
  author = {Jasper Van Hirtum},
  journal= {arXiv preprint arXiv:1710.02287},
  year   = {2020}
}

Comments

Several and drastic changes made to the article. In particular, we now only deal with parallel weight. Moreover, we no longer claim a proven example but instead specify the conditions under which the example is proven to be correct

R2 v1 2026-06-22T22:05:23.561Z