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arXiv · 2410.13719

Reverse stealth construction and its thermodynamic imprints

Cristián Erices·Luis Guajardo·Kristiansen Lara
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Abstract

We study a class of solutions within the context of modified gravity theories, characterized by a non-trivial field that does not generate any back-reaction on the metric. These stealth configurations are effectively defined by the stealth conditions, which correspond to a vanishing stress-energy tensor. In this work, we introduce a novel approach to constructing this class of solutions. In contrast to the standard procedure, the starting point requires satisfying the stealth conditions for a given ansatz independently of the gravitational dynamics. This approach simultaneously determines the non-trivial field and the geometries capable of supporting it as a stealth configuration. Consequently, a gravity model can accommodate a stealth field only if its vacuum solution falls within the geometries permissible under stealth conditions. By applying this reverse procedure in the non-minimal $R\phi^2$ coupling, we recover all previously known stealth configurations and present new solutions. Although it seems intuitive to assume that this ``gravitationally undetectable'' scalar field leaves no physical traces, it remarkably reveals thermodynamic imprints, as its presence screens the black hole mass and modifies the entropy according to the first law.

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Cristián Erices, Luis Guajardo, Kristiansen Lara. 2024-10-17. Reverse stealth construction and its thermodynamic imprints. https://arxiv.org/abs/2410.13719

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