| | |
| | |
Stat |
Members: 3643 Articles: 2'487'895 Articles rated: 2609
28 March 2024 |
|
| | | |
|
Article overview
| |
|
Constraints on fourth order generalized f(R) gravity | Emilio Santos
; | Date: |
8 Aug 2011 | Abstract: | A fourth order generalized f(R) gravity theory (FOG) is considered with the
Einstein-Hilbert action $R+aR^{2}+bR_{mu
u}R^{mu
u},$ $R_{mu
u}$ being
Ricci’{}s tensor and R the curvature scalar. The field equations are applied
to spherical bodies where Newtonian gravity is a good approximation. The result
is that for $0leq asim -b<<R^{2}$, $R$ being the body radius, the
gravitational field outside the body contains two Yukawas, one attractive and
the other one repulsive, in addition to the Newtonian term. For $asim
-b>>R^{2}$ the gravitational field near the body is zero but at distances
greater than $sqrt{a}sim sqrt{-b}$ the field is practically Newtonian. From
the comparison with laboratory experiments I conclude that $sqrt{a}$ and
$sqrt{-b}$ should be smaller than a few millimeters, which excludes any
relevant effect of FOG on stars, galaxies or cosmology. | Source: | arXiv, 1108.1665 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |