Phys. Rev. Lett. 99, 111301 (2007) [3 pages]Nonlocal CosmologyReceived 15 June 2007; revised 18 July 2007; published 14 September 2007 We explore nonlocally modified models of gravity, inspired by quantum loop corrections, as a mechanism for explaining current cosmic acceleration. These theories enjoy two major advantages: they allow a delayed response to cosmic events, here the transition from radiation to matter dominance, and they avoid the usual level of fine-tuning; instead, emulating Dirac’s dictum, the required large numbers come from the large time scales involved. Their solar system effects are safely negligible, and they may even prove useful to the black hole information problem. © 2007 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.99.111301
DOI:
10.1103/PhysRevLett.99.111301
PACS:
95.36.+x, 04.50.+h, 98.80.−k
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.