Spontaneous Lorentz symmetry-breaking constraints in Kalb–Ramond gravity

Ednaldo L. B. Junior; José Tarciso S. S. Junior; Francisco S. N. Lobo; Manuel E. Rodrigues; Diego Rubiera-Garcia; Luís F. Dias da Silva; Henrique A. Vieira

doi:10.1140/epjc/s10052-024-13619-3

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2024) 84: 1257
https://doi.org/10.1140/epjc/s10052-024-13619-3

Regular Article

Spontaneous Lorentz symmetry-breaking constraints in Kalb–Ramond gravity

Ednaldo L. B. Junior¹, José Tarciso S. S. Junior², Francisco S. N. Lobo³^,4^a, Manuel E. Rodrigues²^,5, Diego Rubiera-Garcia⁶, Luís F. Dias da Silva³ and Henrique A. Vieira²

¹ Faculdade de Física, Universidade Federal do Pará, Campus Universitário de Tucuruí, CEP: 68464-000, Tucuruí, Pará, Brazil
² Faculdade de Física, Programa de Pós-Graduação em Física, Universidade Federal do Pará, 66075-110, Belém, Pará, Brazil
³ Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa, Edifício C8, Campo Grande, 1749-016, Lisbon, Portugal
⁴ Departamento de Física, Faculdade de Ciências da Universidade de Lisboa, Edifício C8, Campo Grande, 1749-016, Lisbon, Portugal
⁵ Faculdade de Ciências Exatas e Tecnologia, Universidade Federal do Pará, Campus Universitário de Abaetetuba, 68440-000, Abaetetuba, Pará, Brazil
⁶ Departamento de Física Téorica and IPARCOS, Universidad Complutense de Madrid, 28040, Madrid, Spain

^a fslobo@ciencias.ulisboa.pt

Received: 21 June 2024
Accepted: 17 November 2024
Published online: 4 December 2024

Abstract

In this work, we study timelike and lightlike geodesics in Kalb–Ramond (KR) gravity around a black hole with the goal of constraining the Lorentz symmetry-breaking parameter l. The analysis involves studying the precession of the S2 star periastron orbiting Sgr A* and geodesic precession around the Earth. The ratio of precession frequencies for General Relativity (GR) and KR gravity is computed, with Event Horizon Telescope (EHT) results providing a parameter range for the spontaneous symmetry-breaking of $- 0.185022 \leq l \leq 0.060938$ $-0.185022 \le l \le 0.060938$ . Utilizing the geodesic precession frequency from the Gravity Probe B (GP-B), the l parameter is further constrained to $- 6.30714 \times 10^{- 12} \leq l \leq 3.90708 \times 10^{- 12}$ $-6.30714 \times 10^{-12} \le l \le 3.90708 \times 10^{-12}$ , which is consistent with the Schwarzschild limits. Moreover, for timelike geodesics, the innermost circular orbit (ICO) and innermost stable circular orbit (ISCO) are determined and analyzed to illustrate the impact of the symmetry breaking term. Zoom-whirl obstructions are compared with the Schwarzschild solution. Lower and upper limits of the photon sphere for lightlike geodesics are established to demonstrate the influence of KR gravity on the photon sphere. Additionally, the shadow radius is determined for two observers, one situated at a finite distance from the KR black hole, and the other located at an infinite distance, to constrain the symmetry-breaking parameter l, with comparisons made to EHT results. The bounds for l derived from constraints on the photon sphere radius for lightlike geodesics yield $- 0.0700225 \leq l \leq 0.189785$ $-0.0700225 \le l \le 0.189785$ using EHT data. The findings of this paper align with experimental results in the $l \to 0$ $l \rightarrow 0$ limit.

© The Author(s) 2024

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