Strichartz’s spectral remainder conjecture for compact Heisenberg manifolds

Let M=Γ\HdM=\Gamma\backslash\mathbb{H}_d be a compact Heisenberg manifold, let NM(λ)N_M(\lambda) be the spectral counting function of its sub-Laplacian, and write RM(λ)=NM(λ)−Advol⁡(M)λd+1R_M(\lambda)=N_M(\lambda)-A_d\operatorname{vol}(M)\lambda^{d+1}. Strichartz's conjecture asserts that, as λ→∞\lambda\to\infty, RM(λ)=OM(λd)R_M(\lambda)=O_M(\lambda^d); equivalently, there exists a constant CM>0C_M>0 such that ∣RM(λ)∣≤CMλd|R_M(\lambda)|\le C_M\lambda^d for all sufficiently large λ\lambda.

References

Progress summary

Refreshed
Claimed progress

A September 2026 preprint says the predicted error size is too small, but the exact logarithmic correction remains unknown.

Strichartz’s conjecture concerns the remainder in spectral counting for compact Heisenberg manifolds and predicts an error of order O(λd)O(\lambda^d). The new result claims this polynomial order is unavoidable but that the conjectured logarithmic factor is not sharp.

September 2026 spectral bounds

A preprint titled Spectral asymptotics of sub-Riemannian Laplacians on compact Heisenberg manifolds claims lower bounds excluding the conjectured O(λd)O(\lambda^d) remainder and an upper bound improving the logarithmic factor. The sharp logarithmic factor remains open, and the result is not yet peer reviewed.

Current status (as of September 2026): The conjectured O(λd)O(\lambda^d) remainder is claimed to be false, while the sharp logarithmic remainder remains unresolved and the new bounds await verification.

Sources

Solutions 0

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