Gravitational mechanisms to self-tune the cosmological constant: obstructions and ways forward

Niedermann, Florian; Padilla, Antonio

Abstract

Gravitational models of self-tuning are those in which vacuum energy has no observable effect on spacetime curvature, even though it is a priori unsuppressed below the cut-off. We complement Weinberg's no go theorem by studying field theoretic completions of self-adjustment allowing for broken translations as well as other generalisations, and identify new obstructions. Our analysis uses a very general Källén-Lehmann spectral representation of the exchange amplitude for conserved sources of energy-momentum and exploits unitarity and Lorentz invariance to show that a transition from self-tuning of long wavelength sources to near General Relativity on shorter scales is generically not possible. We search for novel ways around our obstructions and highlight two interesting possibilities. The first is an example of a unitary field configuration on anti-de Sitter space with the desired transition from self-tuning to GR. A second example is motivated by vacuumenergy sequestering.

Citation

Niedermann, F., & Padilla, A. (2017). Gravitational mechanisms to self-tune the cosmological constant: obstructions and ways forward. Physical Review Letters, 119(25), Article 251306. https://doi.org/10.1103/PhysRevLett.119.251306

• Journal Article Type: Article
• Acceptance Date: Nov 17, 2017
• Publication Date: Dec 22, 2017
• Deposit Date: Dec 13, 2017
• Publicly Available Date: Dec 22, 2017
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 119
• Issue: 25
• Article Number: 251306
• DOI: https://doi.org/10.1103/PhysRevLett.119.251306
• Public URL: https://nottingham-repository.worktribe.com/output/901351
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.251306
• Additional Information: © 2017 American Physical Society
• Contract Date: Dec 13, 2017