Yao, Hui2021-07-292021-07-292006https://hdl.handle.net/10092/102252http://dx.doi.org/10.26021/11300We re-formulate and examine T. Buchert’s recent averaging scheme for scalars in cosmological applications of general relativity. The equation thus obtained can be used to describe the averaged quantities of an arbitrary inhomogeneous co-moving region and show the importance of back-reaction. We also study the use of information theory in this averaging framework. Original extensions are mainly made along two lines: the information of inhomogeneity for different scales are compared; the possibility of use of Shannon’s entropy in inhomogeneous cosmology are investigated. We also discuss the non-locality of gravitational energy in inhomogeneous cosmology. Examples of cosmological solutions of Buchert’s averaging scheme are studied.enAll Rights ReservedTheses / Dissertations