English

Quasimodular forms as solutions of Modular differential equations

Number Theory 2021-03-16 v4

Abstract

We study quasimodular forms of depth 4\leq4 and determine under which conditions they occur as solutions of modular differential equations. Furthermore, we study which modular differential equations have quasimodular solutions. We use these results to investigate extremal quasimodular forms as introduced by M. Kaneko and M. Koike further. Especially, we prove a conjecture stated by these authors concerning the divisors of the denominators occurring in their Fourier expansion.

Keywords

Cite

@article{arxiv.2002.02736,
  title  = {Quasimodular forms as solutions of Modular differential equations},
  author = {Peter J. Grabner},
  journal= {arXiv preprint arXiv:2002.02736},
  year   = {2021}
}
R2 v1 2026-06-23T13:34:08.291Z