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arXiv · 2602.23882

Conservative cosmology in scalar-tensor Herglotz $f(R,T)$ gravity

Marek Wazny
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Abstract

The scalar-tensor representation of $f(R,T)$ gravity is extended to incorporate the Herglotz variational principle. The field equations are derived in both the geometric and scalar-tensor frameworks. Although the divergence of the energy-momentum tensor in matter-geometry coupling theories is generally nonvanishing, conservation can be achieved through the introduction of the Herglotz vector. The generalized Friedmann equations in scalar-tensor Herglotz $f(R,T)$ theory are obtained, and a conservative cosmological model is shown to be consistent with late-time observational data. Comparisons with analogous nonconservative models and with the standard $\Lambda$CDM model are also provided.

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Marek Wazny. 2026-02-27. Conservative cosmology in scalar-tensor Herglotz $f(R,T)$ gravity. https://doi.org/10.1088/1361-6382/ae49db

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