Subconvexity problem for symmetric-square L-functions in the level aspect

For a family of tempered cuspidal automorphic representations π\pi of GL2(Q)\mathrm{GL}_2(\mathbb{Q}) with bounded archimedean parameters and conductor q(π)q(\pi) tending to infinity, determine whether there exists a constant δ>0\delta>0 such that, uniformly in the level aspect, L ⁣(12,Sym2π)≪ε,π∞q(Sym2π)14−δ+εL\!\left(\frac12,\mathrm{Sym}^2\pi\right)\ll_{\varepsilon,\pi_\infty}q(\mathrm{Sym}^2\pi)^{\frac14-\delta+\varepsilon} for every ε>0\varepsilon>0.

References

Progress summary

Refreshed
Claimed solved

A September 2026 preprint claims the first improvement over the standard bound, but only for a restricted family and without refereeing.

The problem asks for a bound beating the convexity estimate for symmetric-square LL-functions as the level grows. A 2017 preprint already gave a qualitative improvement for prime-level holomorphic forms, while the latest claim concerns a more specific local-ramification class.

Known results

  • In 2017, a preprint proved L(1/2,Sym⁡2f)≪p1/2−δL(1/2,\operatorname{Sym}^2 f)\ll p^{1/2-\delta} for prime level pp, with some computable δ>0\delta>0, for fixed-weight holomorphic forms with trivial nebentypus.
  • A 2023 result was subconvex in the spectral parameter but remained nearly convex in the level aspect.

September 2026 claimed level-aspect bound

A September 3, 2026 report cites arXiv:2609.04155 as proving exponent 1/4−1/168+o(1)1/4-1/168+o(1) for the stated conductor and local-ramification class, described as the first reported bound of this strength for this GL3\mathrm{GL}_3 setting. The preprint is unrefereed, so the claim remains unverified.

Current status (as of September 2026): A restricted level-aspect subconvexity claim is available, but it is unrefereed and unverified; no broader resolution is established.

Sources

Solutions 0

No solutions have been posted yet.