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arXiv · 1004.3691

Dark energy from modified gravity with Lagrange multipliers

Salvatore Capozziello·Jiro Matsumoto·Shin'ichi Nojiri·Sergei D. Odintsov
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Abstract

We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types ($Λ$CDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is shown that mathematical equivalence between scalar theory and $F(R)$ gravity is broken due to presence of constraint. The cosmological dynamics of $F(R)$ gravity is modified by the second $F_2(R)$ function dictated by the constraint. Dark Energy cosmology is defined by this function while standard $F_1(R)$ function is relevant for local tests (modification of newton regime). A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.

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Salvatore Capozziello, Jiro Matsumoto, Shin'ichi Nojiri, Sergei D. Odintsov. 2010-08-11. Dark energy from modified gravity with Lagrange multipliers. https://doi.org/10.1016/j.physletb.2010.08.030

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