The Milnor–Wood inequality for Euler numbers of hyperbolic 4-manifold bundles

About 1 year old · traced to

Let M=M(e,g)M=M(e,g) be homeomorphic to an R2\mathbb R^2-bundle over a closed orientable surface of genus g>1g>1, with Euler number e=⟨[F],[F]⟩e=\langle[F],[F]\rangle given by the self-intersection of the zero section FF. Milnor–Wood inequality. The inequality

0≤∣e∣≤2g−20\leq |e|\leq 2g-2

is necessary for MM to admit a complete hyperbolic structure. This gives a necessary topological restriction on the Euler number of such bundles; the supplied text does not establish whether the bound is sufficient.

References

Primary source

Michael Kapovich, “Intersection pairing on hyperbolic 4-manifolds”, arXiv:2510.16848 (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.