Morrison–Kawamata cone conjecture

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Let (X/Z,Δ)(X/Z,\Delta) be a klt log Calabi–Yau pair over ZZ, where XX is Q\mathbb{Q}-factorial and Δ\Delta is an R\mathbb{R}-boundary. Let Ae(X/Z)\mathcal{A}^e(X/Z) and Me(X/Z)\mathcal{M}^e(X/Z) denote the effective nef and effective movable cones, respectively. The groups Aut⁡(X/Z,Δ)\operatorname{Aut}(X/Z,\Delta) and PsAut⁡(X/Z,Δ)\operatorname{PsAut}(X/Z,\Delta) act on these cones by pushforward. Morrison–Kawamata cone conjecture. (1) The action of Aut⁡(X/Z,Δ)\operatorname{Aut}(X/Z,\Delta) on Ae(X/Z)\mathcal{A}^e(X/Z) admits a rational polyhedral fundamental domain Π\Pi such that

Ae(X/Z)=⋃g∈Aut⁡(X/Z,Δ)g∗Π\mathcal{A}^e(X/Z)=\bigcup_{g\in\operatorname{Aut}(X/Z,\Delta)}g_*\Pi

and

Int⁡Π∩g∗Int⁡Π=∅\operatorname{Int}\Pi\cap g_*\operatorname{Int}\Pi=\varnothing

unless g∗=1g_*=1. (2) The action of PsAut⁡(X/Z,Δ)\operatorname{PsAut}(X/Z,\Delta) on Me(X/Z)\mathcal{M}^e(X/Z) admits a rational polyhedral fundamental domain Π′\Pi' such that

Me(X/Z)=⋃g∈PsAut⁡(X/Z,Δ)g∗Π′\mathcal{M}^e(X/Z)=\bigcup_{g\in\operatorname{PsAut}(X/Z,\Delta)}g_*\Pi'

and

Int⁡Π′∩g∗Int⁡Π′=∅\operatorname{Int}\Pi'\cap g_*\operatorname{Int}\Pi'=\varnothing

unless g∗=1g_*=1. This is the fundamental-domain form of the Morrison–Kawamata cone conjecture, strengthening the weak finiteness formulation by requiring rational polyhedral fundamental domains.

References

Primary source

Stefano Filipazzi and Fulin Xu, “On the boundedness of elliptic Calabi-Yau 4-folds”, arXiv:2607.27048 (2026).

Additional references

21 papers in this index state this conjecture (2009–2026). The statement above is taken from the most recent of them; the others are arXiv:2602.04499, arXiv:2512.01516, arXiv:2501.10239, arXiv:2405.20899, arXiv:2309.04673, arXiv:2303.07095, arXiv:2101.04093, arXiv:2012.00272, arXiv:2011.08727, arXiv:1908.07928, arXiv:1905.04570, arXiv:1611.00556, and 8 more.

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