University of Cambridge > Talks.cam > Cosmology Lunch > The cosmological constant and inhomogeneity at late times

The cosmological constant and inhomogeneity at late times

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If you have a question about this talk, please contact Dr Sebastien Renaux-Petel.

An observer in a cosmological constant dominated universe will experience de Sitter at late times. Heuristically a positive cosmological constant causes inhomogeneous and anisotropic contributions to dilute as the universe expands, allowing inhomogeneity to be systematically controlled by a late time expansion. I will apply a late time expansion to a Lambda-CDM universe, computing both cosmological solutions and luminosity distance as a function of redshift. The resulting expressions are nonlinear in the inhomogeneity and systematically characterise Lambda-CDM cosmologies which end in cosmological constant domination. Applied to Union 2 supernovae data the leading late time anisotropic correction can be measured, which takes the form of a large scale curvature tensor, whose components are found to be zero at the level of one part in 1000. With more data higher order inhomogeneous corrections can be measured.

This talk is part of the Cosmology Lunch series.

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