The L4-norm problem for Hecke–Maaß eigenforms
Let Γ=SL2(Z)\Gamma=\operatorname{SL}_2(\mathbb{Z})Γ=SL2(Z), let H\mathbb{H}H be the upper half-plane, and let g∈B0(Γ)g\in\mathcal{B}_0(\Gamma)g∈B0(Γ) be a Hecke–Maaß eigenform normalised by…