Brieskorn spheres bound orbit spaces of torus manifolds

Grigory Solomadin

paper

Brieskorn spheres bound orbit spaces of torus manifolds

arXiv:2608.30513

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).

11 pages, 4 figures; comments are welcome