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arXiv · 2105.04687

Gravity with a generalized conformal scalar field: Theory and solutions

Pedro G. S. Fernandes
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Abstract

We naturally extend the theory of gravity with a conformally coupled scalar field by only requiring conformal invariance of the scalar field equation of motion and not of the action. The classically extended theory incorporates a scalar-Gauss-Bonnet sector and has second-order equations of motion, belonging to the Horndeski class. Remarkably, the theory features a purely geometrical field equation that allows for closed-form black hole solutions and cosmologies to be easily found. These solutions permit investigations of in-vogue scalar-Gauss-Bonnet corrections to the gravitational action without the need of resorting to approximations or numerical methods. We discuss on the connection to the recently formulated 4D Einstein-Gauss-Bonnet theory of gravity.

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Pedro G. S. Fernandes. 2021-05-10. Gravity with a generalized conformal scalar field: Theory and solutions. https://doi.org/10.1103/physrevd.103.104065

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