“School of Astronomy”
Back to Papers HomeBack to Papers of School of Astronomy
| Paper IPM / Astronomy / 12435 |
|
||||||
| Abstract: | |||||||
|
We study the volume averaging of inhomogeneous metrics within GR and discuss its
shortcomings, such as gauge dependence, singular behavior as a result of caustics, and
causality violations. To remedy these shortcomings, we suggest some modifications to
this method. As a case study we focus on the inhomogeneous structured FRW model
based on a flat LTB metric. The effect of averaging is then studied in terms of an
effective back-reaction fluid. It is shown that, contrary to the claims in the literature,
the back-reaction fluid behaves like a dark matter component, instead of dark energy,
having a density of the order of 10-5 times the matter density, and, most importantly,
it is gauge-dependent.
Download TeX format |
|||||||
| back to top | |||||||
