English

Circle bundles with PSC over large manifolds

Differential Geometry 2025-10-30 v5 Metric Geometry Symplectic Geometry

Abstract

We construct infinitely many examples of macroscopically large manifolds of dimension m4m \geq 4 equipped with circle bundles whose total spaces admit metrics of positive scalar curvature and have macroscopic dimension at most m/2+1\lceil m/2 \rceil + 1. In particular, we answer a question of Gromov on the existence of circle bundles over enlargeable manifolds whose total spaces admit metrics of positive scalar curvature, in all dimensions. Our constructions are based on techniques from symplectic geometry.

Keywords

Cite

@article{arxiv.2412.01047,
  title  = {Circle bundles with PSC over large manifolds},
  author = {Aditya Kumar and Balarka Sen},
  journal= {arXiv preprint arXiv:2412.01047},
  year   = {2025}
}

Comments

v5. A gap in the proof of Theorem B is fixed. Final version. To appear in GAFA

R2 v1 2026-06-28T20:18:58.865Z