The Toposic Hom Conjecture

About 1 year old · traced to

Let KK be an absolutely finitely generated field, meaning that it is finitely generated over its prime field. Let

C=SchKft⁡[UH⁡−1]\mathscr{C}=\mathbf{Sch}_{K}^{\operatorname{ft}}[\operatorname{UH}^{-1}]

be the localization of the category of finite type KK-schemes at the universal homeomorphisms, and let X,Y∈Ob⁡(C)X,Y\in\operatorname{Ob}(\mathscr{C}). Write Shv⁡(Xeˊt⁡)\operatorname{Shv}(X_{\operatorname{\acute et}}) and Shv⁡(Yeˊt⁡)\operatorname{Shv}(Y_{\operatorname{\acute et}}) for their étale topoi, and let the superscript ∙\bullet denote the class of admissible morphisms specified in the source. The Toposic Hom Conjecture. The natural map

Mor⁡C(X,Y)⟶Mor⁡Shv⁡(Keˊt⁡)∙(Shv⁡(Xeˊt⁡),Shv⁡(Yeˊt⁡))\operatorname{Mor}_{\mathscr{C}}(X,Y)\longrightarrow \operatorname{Mor}_{\operatorname{Shv}(K_{\operatorname{\acute et}})}^\bullet(\operatorname{Shv}(X_{\operatorname{\acute et}}),\operatorname{Shv}(Y_{\operatorname{\acute et}}))

is a bijection. This is the paper's general étale reconstruction statement; the supplied material does not state whether it is proved in full generality, so its resolution remains to be checked.

References

Primary source

Zachary Berens, “Étale Reconstruction for F_p(t)-Schemes”, arXiv:2509.23485 (2025).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.