Two-divisibility of the coefficients of certain weakly holomorphic modular forms
arXiv:1105.0684 · doi:10.1007/s11139-011-9331-0
Abstract
We study a canonical basis for spaces of weakly holomorphic modular forms of weights 12, 16, 18, 20, 22, and 26 on the full modular group. We prove a relation between the Fourier coefficients of modular forms in this canonical basis and a generalized Ramanujan tau-function, and use this to prove that these Fourier coefficients are often highly divisible by 2.
Corrected typos. To appear in the Ramanujan Journal