English

Infinite connected sums, K-area and positive scalar curvature

Differential Geometry 2021-04-29 v3

Abstract

Whyte used the index theory of Dirac operators and Block-Weiberger uniformly finite homology to show that certain infinite connected sums do not carry a metric with nonnegative scalar curvature in their bounded geometry class. His proof uses a coarse version of the A^\hat{A}-class to obstruct such metrics. In this note we prove a version of Whyte's result where a variant of the notion of infinite KK-area, originally due to Gromov, is used to obstruct metrics with positive scalar curvature.

Keywords

Cite

@article{arxiv.math/0408228,
  title  = {Infinite connected sums, K-area and positive scalar curvature},
  author = {Levi Lopes de Lima},
  journal= {arXiv preprint arXiv:math/0408228},
  year   = {2021}
}

Comments

13 pages, no figures, substantially rewritten to accommodate a new version of Theorem 1.1