English

On Bismut Flat Manifolds

Differential Geometry 2023-03-31 v3

Abstract

In this paper, we give a classification of all compact Hermitian manifolds with flat Bismut connection. We show that the torsion tensor of such a manifold must be parallel, thus the universal cover of such a manifold is a Lie group equipped with a bi-invariant metric and a compatible left invariant complex structure. In particular, isosceles Hopf surfaces are the only Bismut flat compact non-K\"ahler surfaces, while central Calabi-Eckmann threefolds are the only simply-connected compact Bismut flat threefolds.

Keywords

Cite

@article{arxiv.1603.07058,
  title  = {On Bismut Flat Manifolds},
  author = {Qingsong Wang and Bo Yang and Fangyang Zheng},
  journal= {arXiv preprint arXiv:1603.07058},
  year   = {2023}
}

Comments

In this 3rd version, we add a lemma on Hermitian surfaces with flat Riemannian connection. References are updated and typos corrected

R2 v1 2026-06-22T13:16:44.571Z