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Palatini formulation of modified gravity with squared scalar curvature

Xinhe Meng·Peng Wang
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Abstract

In this paper we derive the Modified Friedmann equation in the Palatini formulation of $R^2$ gravity. Then we use it to discuss the problem of whether in Palatini formulation a $R^2$ term can drive an inflation. We show that the Palatini formulation of $R^2$ gravity cannot lead to gravity-driven inflation. If considering no zero radiation and matter energy densities, we show that only under rather restrictive assumption about the radiation and matter energy densities there will be a mild power-law inflation $a\sim t^2$.

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Xinhe Meng, Peng Wang. 2004-08-29. Palatini formulation of modified gravity with squared scalar curvature. https://doi.org/10.1023/b%3Agerg.0000048981.40061.63

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