2020/09/30 by James Alvey, Miguel Escudero
Physics and Astronomy · #Axion #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Einstein #General relativity #Global symmetry #Noncommutative and Quantum Gravity Theories #String (physics) #Symmetry (geometry) #Symmetry breaking #Wormhole #hep-ph #hep-th
paper · pdf · doi:10.1007/jhep01(2021)032
published as JHEP 01 (2021) 032 · 12 pages, 4 figures. Matches version to appear in JHEP - minor clarifications added, references updated
openalex created_date 2020/09/14 · arxiv created 2020/12/11 · openalex publication_date 2021/01/07 · arxiv updated 2021/01/12 · openalex updated_date 2026/08/05
A bstract Continuous global symmetries are expected to be broken by gravity, which can lead to important phenomenological consequences. A prime example is the threat that this poses to the viability of the Peccei-Quinn solution to the strong CP problem. In this paper, we explore the impact of wormholes as a source of global symmetry breaking by gravity. We review the current status of wormholes and global symmetries and note that, surprisingly, the axion has a quality problem within non-perturbative Einstein gravity. Although these wormholes lead to a large breaking of global symmetries, we show that their effect is nonetheless relevant for the model building of gauge protected axions. We also find wormhole solutions within two scenarios: (i) an extended global symmetry group within Einstein gravity, and (ii) U(1) wormholes within the low-energy limit of an open String Theory. The former allows us to show that the concept of a global symmetry in General Relativity is somewhat ill-defined. The latter illustrates that for motivated values of the string coupling constant, axions appear to have a quality problem within the open String Theory we consider.