English

Measuring a Kaluza-Klein radius smaller than the Planck length

General Relativity and Quantum Cosmology 2008-11-26 v1 Astrophysics Quantum Physics

Abstract

Hestenes has shown that a bispinor field on a Minkowski space-time is equivalent to an orthonormal tetrad of one-forms together with a complex scalar field. More recently, the Dirac and Einstein equations were unified in a tetrad formulation of a Kaluza-Klein model which gives precisely the usual Dirac-Einstein Lagrangian. In this model, Dirac's bispinor equation is obtained in the limit for which the radius of higher compact dimensions of the Kaluza-Klein manifold becomes vanishingly small compared with the Planck length. For a small but finite radius, the Kaluza-Klein model predicts velocity splitting of single fermion wave packets. That is, the model predicts a single fermion wave packet will split into two wave packets with slightly different group velocities. Observation of such wave packet splits would determine the size of the Kaluza-Klein radius. If wave packet splits were not observed in experiments with currently achievable accuracies, the Kaluza-Klein radius would be at least twenty five orders of magnitude smaller than the Planck length.

Keywords

Cite

@article{arxiv.0708.0521,
  title  = {Measuring a Kaluza-Klein radius smaller than the Planck length},
  author = {Frank Reifler and Randall Morris},
  journal= {arXiv preprint arXiv:0708.0521},
  year   = {2008}
}
R2 v1 2026-06-21T09:04:39.417Z