Graded rings of modular forms (1)
arXiv:2008.13322
Abstract
We study modular forms of some congruence subgroups. In this paper, we treat the cases level is 2-power, 3-power or 5. Structures of graded rings and many identities of infinite sum or infinite product are given. Theory of rational (1/3, 1/4, 1/5 etc) weight or more formally weight modular form are introduced.
arXiv commentKeywords: Modular form, Rational weight, Graded ring