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arXiv · 2312.02784

Friedmann equations in the Codazzi parametrization of Cotton and extended theories of gravity and the Dark Sector

Carlo Alberto Mantica·Luca Guido Molinari
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Abstract

The Friedmann equations of Cotton gravity provide a simple parametrization to reproduce, by tuning a single function, the Friedmann equations of several extensions of gravity, such as f(R), modified Gauss-Bonnet f(G), teleparallel f(T), and more. It also includes the recently proposed Conformal Killing gravity and Mimetic gravity in FRW space-times. The extensions generally have the form of a Codazzi tensor that may be associated to the dark sector. Fixing it by a suitable equation of state accomodates most of the postulated models that extend $\Lambda$CDM, as the Chevallier-Polarski-Lindler model.

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Carlo Alberto Mantica, Luca Guido Molinari. 2023-12-05. Friedmann equations in the Codazzi parametrization of Cotton and extended theories of gravity and the Dark Sector. https://doi.org/10.1103/physrevd.109.044059

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