General second-order scalar-tensor theory and self-tuning

Charmousis, Christos; Copeland, Edmund J.; Saffin, Paul M.; Padilla, Antonio

Abstract

Starting from the most general scalar-tensor theory with second order field equations in four dimensions, we establish the unique action that will allow for the existence of a consistent self-tuning mechanism on FLRW backgrounds, and show how it can be understood as a combination of just four base Lagrangians with an intriguing geometric structure dependent on the Ricci scalar, the Einstein tensor, the double dual of the Riemann tensor and the Gauss-Bonnet combination. Spacetime curvature can be screened from the net cosmological constant at any given moment because we allow the scalar field to break Poincar\'e invariance on the self-tuning vacua, thereby evading the Weinberg no-go theorem. We show how the four arbitrary functions of the scalar field combine in an elegant way opening up the possibility of obtaining non-trivial cosmological solutions.

Citation

Charmousis, C., Copeland, E. J., Saffin, P. M., & Padilla, A. (2012). General second-order scalar-tensor theory and self-tuning. Physical Review Letters, 108(5), Article 051101. https://doi.org/10.1103/PhysRevLett.108.051101

• Journal Article Type: Article
• Acceptance Date: Jan 1, 2012
• Publication Date: Jan 30, 2012
• Deposit Date: Apr 24, 2017
• Publicly Available Date: Apr 24, 2017
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 108
• Issue: 5
• Article Number: 051101
• DOI: https://doi.org/10.1103/PhysRevLett.108.051101
• Public URL: https://nottingham-repository.worktribe.com/output/708985
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.051101
• Additional Information: General Second-Order Scalar-Tensor Theory and Self-Tuning.; Christos Charmousis, Edmund J. Copeland, Antonio Padilla, and Paul M. Saffin, Phys. Rev. Lett. 108, 051101.