English

Spacetime foam: a review

General Relativity and Quantum Cosmology 2023-05-17 v3 High Energy Physics - Theory

Abstract

More than 65 years ago, John Wheeler suggested that quantum uncertainties of the metric would be of order one at the Planck scale, leading to large fluctuations in spacetime geometry and topology, which he termed "spacetime foam." In this review I discuss various attempts to implement this idea and to test it, both theoretically and, to a lesser extent, observationally.

Keywords

Cite

@article{arxiv.2209.14282,
  title  = {Spacetime foam: a review},
  author = {S. Carlip},
  journal= {arXiv preprint arXiv:2209.14282},
  year   = {2023}
}

Comments

42 pages (including 15 pages of referdences); v2: mainly more references, minor fixes; v3: corrected error on growth of triangulations, new discussion of higher order action, some other new references and clarifications

R2 v1 2026-06-28T02:18:46.160Z