A General Relativistic Universe with Structure
Asta Heinesen PhD Oral Candidate in Theoretical Physics Studied under the supervision of Prof David Wiltshire
School of Physical and Chemical Sciences, University of Canterbury
Time & Place
Wed, 16 Oct 2019 15:00:00 NZDT in Engineering Core Meeting Room 119
All are welcome
Cosmology is the discipline of describing overall dynamic properties of the Universe in an averaged or statistical sense in a general relativistic framework.
Many of the conceptual difficulties of macroscopic general relativity have historically been avoided in cosmology by assuming approximate decoupling of scales and imposing exact spatial homogeneity and isotropy for the assumed general relativistic solution for space-time valid on the largest scales. Such assumptions date back to the very founding of general relativistic cosmology.
We shall discuss approaches for taking into account structure on various scales in general relativistic modelling of the Universe. First we formulate a class of covariant averaging schemes designed for describing averaged space-time dynamics, and discuss its relation to existing averaging schemes in the literature. Next we consider observational tests for distinguishing cosmological models formulated in such averaging schemes from competing models. We analyse model dependence in data reduction of conventional analysis and propose alternative methods which are less dependent on assumptions about the underlying metric.