English

The Space of Dirac-Minimal Metrics is Connected in Dimensions 2 and 4

Differential Geometry 2025-12-09 v2

Abstract

Let MM be a closed connected spin manifold. Index theory provides a topological lower bound on the dimension of the kernel of the Dirac operator which depends on the choice of Riemannian metric. Riemannian metrics for which this bound is attained are called Dirac-minimal. We show that the space of Dirac-minimal metrics on MM is connected if MM is of dimension 2 or 4.

Keywords

Cite

@article{arxiv.2508.01420,
  title  = {The Space of Dirac-Minimal Metrics is Connected in Dimensions 2 and 4},
  author = {Bernd Ammann and Mattias Dahl},
  journal= {arXiv preprint arXiv:2508.01420},
  year   = {2025}
}