Exact Solution to the Averaging Problem in Cosmology
Abstract
The exact solution of a twoscale Buchert average of the Einstein equations is derived for an inhomogeneous universe that represents a close approximation to the observed universe. The two scales represent voids, and the bubble walls surrounding them within which clusters of galaxies are located. As described elsewhere [New J. Phys. 9, 377 (2007)NJOPFM1367263010.1088/13672630/9/10/377], apparent cosmic acceleration can be recognized as a consequence of quasilocal gravitational energy gradients between observers in bound systems and the volumeaverage position in freely expanding space. With this interpretation, the new solution presented here replaces the Friedmann solutions, in representing the average evolution of a matterdominated universe without exotic dark energy, while being observationally viable.
 Publication:

Physical Review Letters
 Pub Date:
 December 2007
 DOI:
 10.1103/PhysRevLett.99.251101
 arXiv:
 arXiv:0709.0732
 Bibcode:
 2007PhRvL..99y1101W
 Keywords:

 98.80.Jk;
 95.36.+x;
 Mathematical and relativistic aspects of cosmology;
 Dark energy;
 General Relativity and Quantum Cosmology;
 Astrophysics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 4 pages