Cosmology: a bird's eye view
Abstract
In this essay we discuss the difference in views of the Universe as seen by two different observers. While one of the observers follows a geodesic congruence defined by the geometry of the cosmological model, the other observer follows the fluid flow lines of a perfect fluid with a linear equation of state. We point out that the information these observers collect regarding the state of the Universe can be radically different; while one observes a non-inflating ever-expanding ever-lasting universe, the other observer can experience a dynamical behaviour reminiscent to that of quintessence or even that of a phantom cosmology leading to a 'big rip' singularity within finite time (but without the need for exotic forms of matter).
Cite
@article{arxiv.gr-qc/0605089,
title = {Cosmology: a bird's eye view},
author = {Alan A. Coley and Sigbjorn Hervik and Woei Chet Lim},
journal= {arXiv preprint arXiv:gr-qc/0605089},
year = {2008}
}
Comments
5 pages; received an honorable mention in the Gravity Research Foundation Essay Competition, 2006