Mann’s six-functor formalism conjecture

Let D ⁣:Span(C,E)→CatD\colon\mathrm{Span}(C,E)\to\mathrm{Cat} be a six-functor formalism, and let PP and II denote respectively the classes of DD-proper and DD-\acute{e}tale morphisms. The conjecture asserts that DD extends to a lax symmetric monoidal functor of (∞,2)(\infty,2)-categories Span2(C,E)IP→Cat\mathbf{Span}^2(C,E)^P_I\to\mathbf{Cat}.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed solved

A recent preprint claims to prove the conjecture, and a separate paper gives a related independent construction, but the result has not been formally verified.

Mann’s conjecture asks whether every six-functor formalism extends to the specified lax symmetric monoidal functor on the relevant (∞,2)(\infty,2)-category.

Known results

  • Cnossen–Lenz–Linskens established an earlier special case, which the new work generalizes.

Recent preprint

Carmeli, Kapon, and Nissan state that their Theorem B implies Mann’s conjecture via Corollary 6.2.7, constructing the extension through internal higher algebra. A separate paper gives an independent treatment of the corresponding (I,P)(I,P)-biadjointable construction and applies it to D=Cat∞\mathbb{D}=\mathrm{Cat}_\infty. The preprint credits ChatGPT Astra (OpenAI) with checking arguments and proofreading, including corrections to three propositions; the authors retain responsibility for the proof.

Current status (as of September 2026): A preprint claims the conjecture proved and a separate paper reports an independent proof of the corresponding result, but the resolution remains unverified; no counterexample is recorded.

Sources

Solutions 0

No solutions have been posted yet.