Off-shell dark matter: a cosmological relic of quantum gravity

Saravani, Mehdi; Afshordi, Niayesh

Abstract

We study a novel proposal for the origin of cosmological cold dark matter (CDM) which is rooted in the quantum nature of spacetime. In this model, off-shell modes of quantum fields can exist in asymptotic states as a result of spacetime nonlocality (expected in generic theories of quantum gravity), and play the role of CDM, which we dub off-shell dark matter (OfDM). However, their rate of production is suppressed by the scale of non-locality (e.g. Planck length). As a result, we show that OfDM is only produced in the first moments of big bang, and then effectively decouples (except through its gravitational interactions). We examine the observational predictions of this model: In the context of cosmic inflation, we show that this proposal relates the reheating temperature to the inflaton mass, which narrows down the uncertainty in the number of e-foldings of specific inflationary scenarios. We also demonstrate that OfDM is indeed cold, and discuss potentially observable signatures on small scale matter power spectrum.

Citation

Saravani, M., & Afshordi, N. (2017). Off-shell dark matter: a cosmological relic of quantum gravity. Physical Review D, 95(4), Article 043514. https://doi.org/10.1103/PhysRevD.95.043514

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2017
• Online Publication Date: Feb 17, 2017
• Publication Date: Feb 15, 2017
• Deposit Date: Jul 4, 2017
• Publicly Available Date: Jul 4, 2017
• Journal: Physical Review D
• Print ISSN: 2470-0010
• Electronic ISSN: 2470-0029
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 95
• Issue: 4
• Article Number: 043514
• DOI: https://doi.org/10.1103/PhysRevD.95.043514
• Keywords: Dark matter, Quantum gravity
• Public URL: https://nottingham-repository.worktribe.com/output/845769
• Publisher URL: https://link.aps.org/doi/10.1103/PhysRevD.95.043514
• Additional Information: ©2017 American Physical Society