Enhanced derived-Picard-group conjecture for closed-surface Fukaya categories

Let Σg\Sigma_g be a closed oriented surface of genus g≥2g\ge 2, let Λ\Lambda be the complex Novikov field, and let Fg\mathscr F_g be the split-closed, strictly unobstructed, two-periodic Fukaya category of Σg\Sigma_g over Λ\Lambda. Determine whether DPic⁡Λ(Fg)\operatorname{DPic}_{\Lambda}(\mathscr F_g) is isomorphic to (H1(Σg;Λ×)⋊π0Diff⁡+(Σg))×Z/2Z\bigl(H^1(\Sigma_g;\Lambda^\times)\rtimes\pi_0\operatorname{Diff}^+(\Sigma_g)\bigr)\times\mathbb Z/2\mathbb Z.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Open

No independently verified solution has appeared, and the general question remains open.

The conjecture seeks a complete description of the derived Picard group of a closed-surface Fukaya category, including recovery of the surface genus. The proposed description is

(H1(Σg;Λ×)⋊π0Diff+(Σg))×Z/2Z.(H^{1}(\Sigma_g;\Lambda^{\times})\rtimes\pi_{0}\mathrm{Diff}^{+}(\Sigma_g))\times\mathbb{Z}/2\mathbb{Z}.

Known results

  • A June 2020 paper proves that, for g≥2g\ge 2, spherical objects with nonzero Chern character come from simple closed curves with rank-one local systems, and gives a surjection Auteq(DπF(Σg))→Γ(Σg)\mathrm{Auteq}(D^{\pi}\mathcal{F}(\Sigma_g))\to\Gamma(\Sigma_g).
  • The same paper explicitly leaves the full autoequivalence-group description as a conjecture, proposing H1(Σg;Λ∗)⋊Γ(Σg)H^{1}(\Sigma_g;\Lambda^{*})\rtimes\Gamma(\Sigma_g).

September 2026 preprint

Dongjian Wu and Nantao Zhang report the claimed closed-surface formula and genus recovery in a September 2026 preprint. No independent mathematical assessment was found, so this does not establish a solution.

Current status (as of September 2026): The earlier partial results are established, but the enhanced conjecture remains open because the new resolution claim is unverified.

Sources

Solutions 0

No solutions have been posted yet.