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arXiv · 2312.12393

The hybrid cosmology in the scalar-tensor representation of $f(\mathcal{G},T)$ gravity

Adam Z. Kaczmarek·Dominik Szczęśniak
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Abstract

In this work, the $f(\mathcal{G},T)$ theory of gravity is recast in terms of the $\phi$ and $\psi$ fields within the scalar-tensor formulation, where $\mathcal{G}$ is the Gauss-Bonnet term and $T$ denotes the trace of the energy-momentum tensor. The general aspects of the introduced reformulation are discussed and the reconstruction of the cosmological scenarios is presented, focusing on the so-called hybrid evolution. As a result, the scalar-tensor $f(\mathcal{G},T)$ theory is successfully reconstructed for the early and late time approximations with the corresponding potentials. The procedure of recovering the $f(\mathcal{G},T)$ theory in the original formulation is performed for the late time evolution and a specific quadratic potential. The scalar-tensor formulation introduced herein not only facilitates the description of various cosmic phases but also serves as a viable alternative portrayal of the $f(\mathcal{G},T)$ gravity which can be viewed as an extension of the well-established scalar Einstein-Gauss-Bonnet gravity.

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Adam Z. Kaczmarek, Dominik Szczęśniak. 2023-12-19. The hybrid cosmology in the scalar-tensor representation of $f(\mathcal{G},T)$ gravity. https://arxiv.org/abs/2312.12393

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