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arXiv · 2509.24890

On energy-momentum conservation in non-minimal geometry-matter coupling theories

Gonzalo J. Olmo·Miguel A. S. Pinto
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Abstract

In this work, we discuss the conditions that allow the establishment of an equivalence between $f(R,T)=R+\lambda h(T)$ gravity models and General Relativity (GR) coupled to a modified matter sector. We do so by considering a $D$-dimensional spacetime and the matter sector to be described by nonlinear electrodynamics and/or a scalar field. We find that, for this particular family of models, the action and field equations can indeed be written in terms of a modified matter source within GR. However, when several matter sources are combined, this interpretation is no longer possible if $h(T)$ is a nonlinear function, due to the emergence of crossed terms that mix together the scalar and vector sectors.

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Gonzalo J. Olmo, Miguel A. S. Pinto. 2025-09-29. On energy-momentum conservation in non-minimal geometry-matter coupling theories. https://doi.org/10.3390/universe11120386

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