Brieskorn spheres bound orbit spaces of torus manifolds

Grigory Solomadin

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arXiv · 2608.30513

Brieskorn spheres bound orbit spaces of torus manifolds

Grigory Solomadin

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Abstract

We construct a smooth, equivariantly formal, simply connected torus $8$-manifold over a contractible $4$-manifold with the boundary a Brieskorn homology $3$-sphere having a nontrivial fundamental group. We prove extension to a torus graph for GKM graphs of GKM$_{4}$ manifolds in complexity $2$, and $3$ under a finite fundamental group assumption (that is not satisfied, in general).

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Grigory Solomadin. 2026-08-31. Brieskorn spheres bound orbit spaces of torus manifolds. https://arxiv.org/abs/2608.30513

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