English

Instantons, Fermions and Chern-Simons Terms

High Energy Physics - Theory 2009-12-04 v2

Abstract

In five spacetime dimensions, instantons are finite energy, solitonic particles. We describe the dynamics of these objects in the presence of a Chern-Simons interaction. For U(N) instantons, we show that the 5d Chern-Simons term induces a corresponding Chern-Simons term in the ADHM quantum mechanics. For SU(N) instantons, we provide a description in terms of geodesic motion on the instanton moduli space, modified by the presence of a magnetic field. We show that this magnetic field is equal to the first Chern character of an index bundle. All of these results are derived by a simple method which follows the fate of zero modes as fermions are introduced, made heavy, and subsequently integrated out.

Keywords

Cite

@article{arxiv.0804.1772,
  title  = {Instantons, Fermions and Chern-Simons Terms},
  author = {Benjamin Collie and David Tong},
  journal= {arXiv preprint arXiv:0804.1772},
  year   = {2009}
}

Comments

12 pages. v2: factor of 2 corrected

R2 v1 2026-06-21T10:29:45.224Z