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arXiv · 1511.00491

Non-minimal derivative coupling gravity in cosmology

Burin Gumjudpai·Phongsaphat Rangdee
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Abstract

We give a brief review of the non-minimal derivative coupling (NMDC) scalar field theory in which there is non-minimal coupling between the scalar field derivative term and the Einstein tensor. We assume that the expansion is of power-law type or super-acceleration type for small redshift. The Lagrangian includes the NMDC term, a free kinetic term, a cosmological constant term and a barotropic matter term. For a value of the coupling constant that is compatible with inflation, we use the combined WMAP9 (WMAP9+eCMB+BAO+ $H_0$) dataset, the PLANCK+WP dataset, and the PLANCK $TT,TE,EE$+lowP+Lensing+ext datasets to find the value of the cosmological constant in the model. Modeling the expansion with power-law gives a negative cosmological constants while the phantom power-law (super-acceleration) expansion gives positive cosmological constant with large error bar. The value obtained is of the same order as in the $Λ$CDM model, since at late times the NMDC effect is tiny due to small curvature.

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Burin Gumjudpai, Phongsaphat Rangdee. 2020-01-12. Non-minimal derivative coupling gravity in cosmology. https://doi.org/10.1007/s10714-015-1985-2

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