TITLE:
Unimodular Gravity and Averaging
AUTHORS:
Alan Coley, Johan Brannlund, Joey Latta
KEYWORDS:
Inhomogeneous Cosmology; Averaging; Unimodular Gravity
JOURNAL NAME:
Journal of Modern Physics,
Vol.3 No.3,
March
28,
2012
ABSTRACT: The question of the averaging of inhomogeneous spacetimes in cosmology is important for the correct interpretation of cosmological data. In this paper a conceptually simpler approach to averaging in cosmology is suggested, based on the averaging of scalars within unimodular gravity. As an illustration, the example of an exact spherically symmetric dust model is considered, and it is shown that within this approach averaging introduces correlations (corrections) to the effective dynamical evolution equation in the form of a spatial curvature term.