Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
2010-05-14
Gen.Rel.Grav.43:847-869,2011
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
18 pages, 16 figures, 11 tables
Scientific paper
10.1007/s10714-010-1101-6
We follow approach of induced matter theory for 5D vacuum BD, introduce induced matter and potential in 4D hypersurfaces, and employ generalized FRW type solution. We confine ourselves to scalar field and scale factors be functions of the time. This makes the induced potential, by its definition, vanishes. When the scale factor of fifth dimension and scalar field are not constants, 5D eqs for any geometry admit a power law relation between scalar field and scale factor of fifth dimension. Hence the procedure exhibits that 5D vacuum FRW like eqs are equivalent, in general, to corresponding 4D vacuum ones with the same spatial scale factor but new scalar field and coupling constant. We show that 5D vacuum FRW like eqs or its equivalent 4D vacuum ones admit accelerated solutions. For constant scalar field, eqs reduce to usual FRW eqs with typical radiation dominated universe. For this situation we obtain dynamics of scale factors for any geometry without any priori assumption. For nonconstant scalar fields and spatially flat geometries, solutions are found to be power law and exponential ones. We also employ weak energy condition for induced matter, that allows negative/positive pressures. All types of solutions fulfill WEC in different ranges. The power law solutions with negative/positive pressures admit both decelerating and accelerating ones. Some solutions accept shrinking extra dimension. By considering nonghost scalar fields and recent observational measurements, solutions are more restricted. We illustrate that accelerating power law solutions, which satisfy WEC and have nonghost fields, are compatible with recent observations in ranges -4/3 < \omega
Bahrehbakhsh Amir F.
Farhoudi Mehrdad
Shojaie Hossein
No associations
LandOfFree
FRW Cosmology From Five Dimensional Vacuum Brans-Dicke Theory does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with FRW Cosmology From Five Dimensional Vacuum Brans-Dicke Theory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and FRW Cosmology From Five Dimensional Vacuum Brans-Dicke Theory will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-519310