Euclidean wormholes, baby universes, and their impact on particle physics and cosmology

• Verfasst von: Hebecker, Arthur [VerfasserIn]
• Verfasst von: Mikhail, Thomas [VerfasserIn]
• Verfasst von: Soler, Pablo [VerfasserIn]
• Titel: Euclidean wormholes, baby universes, and their impact on particle physics and cosmology
• Verf.angabe: Arthur Hebecker, Thomas Mikhail and Pablo Soler
• E-Jahr: 2018
• Jahr: 08 October 2018
• Umfang: 35 S.
• Teil: volume:5
• Teil: year:2018
• Teil: elocationid:35
• Teil: extent:35
• Fussnoten: Gesehen am 04.12.2020
• Titel Quelle: Enthalten in: Frontiers in astronomy and space sciences
• Ort Quelle: Lausanne : Frontiers Media, 2014
• Jahr Quelle: 2018
• Band/Heft Quelle: 5(2018), Artikel-ID 35
• ISSN Quelle: 2296-987X
• DOI: doi:10.3389/fspas.2018.00035
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: axions
• Sach-SW: Euclidean wormhole
• Sach-SW: gravitational instanton
• Sach-SW: inflation
• Sach-SW: particle physics -cosmology connection
• Sach-SW: Quantum Gravity
• Sach-SW: string theory
• Sach-SW: weak gravity conjecture
• K10plus-PPN: 1582183716
• K10plus-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

The euclidean path integral remains, in spite of its familiar problems, an important approach to quantum gravity. One of its most striking and obscure features is the appearance of gravitational instantons or wormholes. These renormalize all terms in the Lagrangian and cause a number of puzzles or even deep inconsistencies, related to the possibility of nucleation of "baby universes". In this review, we revisit the early controversies surrounding these issues as well as some of the more recent discussions of the phenomenological relevance of gravitational instantons. In particular, wormholes are expected to break the shift symmetries of axions or Goldstone bosons non-perturbatively. This can be relevant to large-field inflation and connects to arguments made on the basis of the Weak Gravity or Swampland conjectures. It can also affect Goldstone bosons which are of physical interest in the context of the strong CP problem or as dark matter.