Lyubeznik's étale cohomological dimension conjecture

From papers

Let UU be a scheme of finite type over a separably closed field K\mathbb{K}. Write eˊcd(U)\operatorname{\acute{e}cd}(U) for its étale cohomological dimension and qccd(U)\operatorname{qccd}(U) for its quasicoherent cohomological dimension.

Lyubeznik's conjecture.

eˊcd(U)dim(U)+qccd(U).\operatorname{\acute{e}cd}(U) \geq \dim(U)+\operatorname{qccd}(U).

The conjecture compares étale and quasicoherent cohomological dimensions. It was motivated by examples in which the étale-cohomological lower bound is at least as strong as the quasicoherent one; its resolution is not specified here.

Progress summary

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

Sources & referencesView supporting material

Primary source

Manolis C. Tsakiris and Matteo Varbaro, “Étale and Quasicoherent Cohomological Dimensions of Subspace Arrangements”, arXiv:2606.20448 (2026).

Additional references

4 papers in this index state this conjecture (2010–2026). The statement above is taken from the most recent of them; the others are arXiv:2106.09796, arXiv:1011.6648, arXiv:1007.5440.

Solutions 0

No solutions have been posted yet.