The non-CM Fourier coefficient conjecture for odd discriminant level

About 1 year old · traced to

Let kk be an integer with k≥3k\geq 3, and let D=p1⋯pℓD=p_1\cdots p_\ell be an odd discriminant. Let SkEll(Γ1(D),ωE/Q)S_k^{\mathrm{Ell}}(\Gamma_1(D),\omega_{E/\mathbb{Q}}) denote the space of elliptic cusp forms of weight kk, level Γ1(D)\Gamma_1(D), and nebentypus ωE/Q\omega_{E/\mathbb{Q}}. A normalized newform in this space is non-CM if it does not have complex multiplication. The non-CM Fourier coefficient conjecture. If this space contains a non-CM normalized newform, then at least one such newform ff satisfies

af(pi)≠±pi(k−1)/2for every i.a_f(p_i)\neq \pm p_i^{(k-1)/2}\quad\text{for every }i.

Here af(pi)a_f(p_i) is the pip_i-th Fourier coefficient of ff. This conjecture asserts that, among the available non-CM newforms, one can find a form avoiding the CM-type extremal values at every prime dividing the odd discriminant. The source provides no resolution, so the conjecture is recorded as open.

References

Primary source

Shuji Horinaga, Yota Maeda and Takuya Yamauchi, “The Kodaira dimension of even-dimensional ball quotients”, arXiv:2507.22203 (2025).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.