Year: 2020
Type: article
Abstract: In the wake of interest to find black hole solutions with scalar hair, we investigate the effects of disformal transformations on static spherically symmetric spacetimes with a nontrivial scalar field. In particular, we study solutions that have a singularity in a given frame, while the action is regular. We ask if there exists a different choice of field variables such that the geometry and the fields are regular. We find that in some cases disformal transformations can remove a singularity from the geometry or introduce a new horizon. This is possible since the Weyl tensor is not invariant under a general disformal transformation. There exists a class of metrics which can be brought to Minkowksi geometry by a disformal transformation, which may be called disformally flat metrics. We investigate three concrete examples from massless scalar fields to Horndeski theory for which the singularity can be removed from the geometry. This might indicate that no physical singularity is present. We also propose a disformal invariant tensor.
Authors: Guillem Domènech, Atsushi Naruko, Misao Sasaki, Christof Wetterich
Institutions: Heidelberg University, Tohoku University, Kyoto University, Yukawa Institute for Theoretical Physics, Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Kavli Institute for the Physics and Mathematics of the Universe, National Taiwan University, Chinese Academy of Sciences, Institute of Theoretical Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2993303333