Homeomorphism and codimension conjecture for Kähler–Ricci flow limits

Let MmM^m be a compact Kähler manifold with semiample canonical bundle and Kodaira dimension n=κ(M)n=\kappa(M) satisfying 0<n<m0<n<m. Let f:MNf:M\to N be its Iitaka fibration onto a normal projective variety NnN^n, let NN^\circ be the complement of the discriminant locus, and let (Z,dZ)(Z,d_Z) be the metric completion of (N,ωcan)(N^\circ,\omega_{\rm can}), where ωcan\omega_{\rm can} is the canonical metric arising from the normalized Kähler–Ricci flow tω(t)=Ric(ω(t))ω(t)\frac{\partial}{\partial t}\omega(t)=-\operatorname{Ric}(\omega(t))-\omega(t). Kähler–Ricci flow collapse conjecture. In the Kähler–Ricci flow setup, (M,ω(t))(Z,dZ)(M,\omega(t))\to (Z,d_Z) in the Gromov–Hausdorff topology. Furthermore, ZZ is homeomorphic to NN and Z\NZ\backslash N^\circ has real Hausdorff codimension at least 22 inside (Z,dZ)(Z,d_Z). This predicts the topology and metric codimension of the singular set in the limiting space of the normalized Kähler–Ricci flow; convergence to a compact metric completion is known, while the full homeomorphism and codimension assertions remain open in general.

Sources & referencesView supporting material

Primary source

Yang Li and Valentino Tosatti, “On the collapsing of Calabi-Yau manifolds and Kähler-Ricci flows”, arXiv:2107.00836 (2024).

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.