English

An essential relation between Einstein metrics, volume entropy, and exotic smooth structures

Differential Geometry 2022-02-15 v2 Geometric Topology

Abstract

We show that the minimal volume entropy of closed manifolds remains unaffected when nonessential manifolds are added in a connected sum. We combine this result with the stable cohomotopy invariant of Bauer-Furuta in order to present an infinite family of four-manifolds with the following properties: 1) They have positive minimal volume entropy. 2) They satisfy a strict version of the Gromov-Hitchin-Thorpe inequality, with a minimal volume entropy term. 3) They nevertheless admit infinitely many distinct smooth structures for which no compatible Einstein metric exists.

Keywords

Cite

@article{arxiv.0807.1187,
  title  = {An essential relation between Einstein metrics, volume entropy, and exotic smooth structures},
  author = {Michael Brunnbauer and Masashi Ishida and Pablo Suárez-Serrato},
  journal= {arXiv preprint arXiv:0807.1187},
  year   = {2022}
}

Comments

12 pages, v2; two references added, to appear in Math. Research Letters

R2 v1 2026-06-21T10:58:24.495Z