English

A three dimensional ball quotient

Algebraic Geometry 2012-01-04 v1 Number Theory

Abstract

In connection with our previous investigation about Siegel threefolds which admit a Calabi--Yau model, we consider ball quotients which belong to the unitary group \U(1,3)\U(1,3). In this paper we determine a very particular example of a Picard modular variety of general type. Really we determine the ring of modular forms. This algebra has 25 generators, 15 modular forms BiB_i of weight one and ten modular forms CjC_j of weight 2. Both will appear as Borcherds products. We determine the ideal of relations. The forms CiC_i are cuspidal. Their squares define holomorphic differential forms on the non-singular models.

Keywords

Cite

@article{arxiv.1201.0131,
  title  = {A three dimensional ball quotient},
  author = {Eberhard Freitag and Riccardo Salvati Manni},
  journal= {arXiv preprint arXiv:1201.0131},
  year   = {2012}
}

Comments

35 pages

R2 v1 2026-06-21T19:58:33.945Z