English

Tautological classes and smooth bundles over BSU(2)

Algebraic Topology 2020-11-24 v2 Geometric Topology

Abstract

For a Lie group G and a smooth manifold W, we study the difference between smooth actions of G on W and bundles over the classifying space of G with fiber W and structure group Diff(W). In particular, we exhibit smooth manifold bundles over BSU(2) that are not induced by an action. The main tool for reaching this goal is a technical result that gives a constraint for the values of tautological classes pulled back to the cohomology of BSU(2) along a map induced by an action.

Keywords

Cite

@article{arxiv.1802.02248,
  title  = {Tautological classes and smooth bundles over BSU(2)},
  author = {Jens Reinhold},
  journal= {arXiv preprint arXiv:1802.02248},
  year   = {2020}
}

Comments

final version, to appear in Proceedings of the American Mathematical Society

R2 v1 2026-06-23T00:13:55.354Z