Backreaction as an alternative to dark energy and modified gravity

Syksy Rasanen

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arXiv · 1012.0784

Backreaction as an alternative to dark energy and modified gravity

Syksy Rasanen

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Abstract

The predictions of homogeneous and isotropic cosmological models with ordinary matter and gravity are off by a factor of two in the late universe. One possible explanation is the known breakdown of homogeneity and isotropy due to the formation of non-linear structures. We review how inhomogeneities affect the average expansion rate and can lead to acceleration, and consider a semi-realistic model where the observed timescale of ten billion years emerges from structure formation. We also discuss the relation between the average expansion rate and observed quantities.

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Syksy Rasanen. 2010-12-03. Backreaction as an alternative to dark energy and modified gravity. https://arxiv.org/abs/1012.0784

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