English

Geometric non-commutative geometry

Geometric Topology 2020-02-07 v2 Differential Geometry

Abstract

In a recent paper, the authors proved that no spin foliation on a compact enlargeable manifold with Hausdorff homotopy graph admits a metric of positive scalar curvature on its leaves. This result extends groundbreaking results of Lichnerowicz, Gromov and Lawson, and Connes on the non-existence of metrics of positive scalar curvature. In this paper we review in more detail the material needed for the proof of our theorem and we extend our non-existence results to non-compact manifolds of bounded geometry. We also give a first obstruction result for the existence of metric with (not necessarily uniform) leafwise PSC in terms of the A-hat class in Haefliger cohomology.

Keywords

Cite

@article{arxiv.1909.00063,
  title  = {Geometric non-commutative geometry},
  author = {Moulay Tahar Benameur and James L. Heitsch},
  journal= {arXiv preprint arXiv:1909.00063},
  year   = {2020}
}
R2 v1 2026-06-23T11:01:45.434Z