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arXiv · 2411.11588

On causality and its violation in $f(R,\lm,T)$ gravity

J. S. Gonçalves·A. F. Santos
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Abstract

In this paper, $f(R,\lm, T)$ gravity is considered. It is a generalization of the theories $f(R,T)$ and $f(R, \lm)$. This modified theory of gravity exhibits strong geometry-matter coupling. The problem of causality and its violation is verified in this model. Such analysis is carried out using G\"{o}del-type solutions considering different types of matter. It is shown that this model allows both causal and non-causal solutions. These solutions depend directly on the content of matter present in the universe. For the non-causal solution, a critical radius is calculated, beyond which causality is violated. Taking different matter contents, an infinite critical radius emerges that leads to a causal solution. To obtain a causal solution, a natural relationship arises between the parameters of the theory.

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J. S. Gonçalves, A. F. Santos. 2024-11-18. On causality and its violation in $f(R,\lm,T)$ gravity. https://arxiv.org/abs/2411.11588

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