Cosmic acceleration and stars in an asymptotically Ricci flat universe
Abstract
We analyze the evolution of a Friedmann-Robertson-Walker spacetime within the framework of f (R ) metric gravity using an exponential model. We show that f (R ) gravity may lead to a vanishing effective cosmological constant in the far future (i.e., R →0 ) and yet produce a transient accelerated expansion at present time with a potentially viable cosmological history. This property is reminiscent of quintessence dark energy but contrasts with several f (R ) models in that most of them produce a nonvanishing effective cosmological constant asymptotically in time (R →4 Λeff). We also show that relativistic stars in asymptotically flat spacetimes can be supported within this framework without encountering any singularity, notably in the Ricci scalar R .
- Publication:
-
Physical Review D
- Pub Date:
- October 2018
- DOI:
- 10.1103/PhysRevD.98.084045
- arXiv:
- arXiv:1711.08026
- Bibcode:
- 2018PhRvD..98h4045J
- Keywords:
-
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 12 pages, 18 figures in 9 panels