English

Generating Picard modular forms by means of invariant theory

Algebraic Geometry 2022-03-01 v2

Abstract

We use the description of the Picard modular surface for discriminant 3-3 as a moduli space of curves of genus 33 to generate all vector-valued Picard modular forms from bi-covariants for the action of GL2{GL}_2 on the space of pairs of binary forms of bidegree (4,1)(4,1). The universal binary forms of degree 44 and 11 correspond to a meromorphic modular form of weight (4,2)(4,-2) and a holomorphic Eisenstein series of weight (1,1)(1,1).

Keywords

Cite

@article{arxiv.2110.00849,
  title  = {Generating Picard modular forms by means of invariant theory},
  author = {Fabien Cléry and Gerard van der Geer},
  journal= {arXiv preprint arXiv:2110.00849},
  year   = {2022}
}

Comments

41 pages; minor changes. To appear in PAMQ