Ghost of vector fields in compact stars

Silva, Hector O.; Coates, Andrew; Ramazanoǧlu, Fethi M.; Sotiriou, Thomas P.

Abstract

Spontaneous scalarization is a mechanism that allows a scalar field to go undetected in weak gravity environments and yet develop a nontrivial configuration in strongly gravitating systems. At the perturbative level it manifests as a tachyonic instability around spacetimes that solve Einstein's equations. The endpoint of this instability is a nontrivial scalar field configuration that can significantly modify a compact object's structure and can produce observational signatures of the scalar field's presence. Does such a mechanism exists for vector fields? Here we revisit the model that constitutes the most straightforward generalization of the original scalarization model to a vector field and perform a perturbative analysis. We show that a ghost appears as soon as the square of the naive effective mass squared becomes negative anywhere. This result poses a serious obstacle in generalizing spontaneous scalarization to vector fields.

Citation

Silva, H. O., Coates, A., Ramazanoǧlu, F. M., & Sotiriou, T. P. (2022). Ghost of vector fields in compact stars. Physical Review D, 105(2), Article 024046. https://doi.org/10.1103/PhysRevD.105.024046

• Journal Article Type: Article
• Acceptance Date: Dec 10, 2021
• Online Publication Date: Jan 20, 2022
• Publication Date: Jan 15, 2022
• Deposit Date: Jan 21, 2022
• Publicly Available Date: Jan 25, 2022
• Journal: Physical Review D
• Print ISSN: 2470-0010
• Electronic ISSN: 2470-0029
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 105
• Issue: 2
• Article Number: 024046
• DOI: https://doi.org/10.1103/PhysRevD.105.024046
• Public URL: https://nottingham-repository.worktribe.com/output/7284170
• Publisher URL: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.105.024046