Kerr–Sen-like Lorentz violating black holes and superradiance phenomena

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2022-05, Vol.82 (5), p.1-17, Article 411
• Main Authors: Jha, Sohan Kumar, Rahaman, Anisur
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Black holes; Bumblebees; Deviation; Elementary Particles; Frequency ranges; Gravity; Hadrons; Heavy Ions; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Parameter modification; Phase transitions; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Radiation; Regular Article - Theoretical Physics; Scalars; Scattering; Spacetime; String Theory; Symmetry; Theory of relativity
• ISSN: 1434-6052; 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10307-y

A Kerr–Sen-like black hole solution results from Einstein-bumblebee gravity. It contains a Lorentz violating (LV) parameter that enters when the bumblebee field receives vacuum expectation value through a spontaneously breaking of the symmetry of the classical action. The geometrical structure concerning the singularity of this spacetime is studied with reference to the parameters involved in the Kerr–Sen-like metric. We introduce this Einstein-bumblebee modified gravity to probe the role of spontaneous Lorentz violation on the superradiance scattering phenomena and the instability associated with it. We observe that for the low-frequency range of the scalar wave the superradiance scattering gets enhanced when the Lorentz-violating parameter ℓ takes the negative values and it reduces when values of ℓ are positive. The study of the black hole bomb issue reveals that for the negative values of ℓ , the parameter space of the scalar field instability increase prominently, however, for its positive values, it shows a considerable reduction. We also tried to put constraints on the parameters contained in the Kerr–Sen-like black hole by comparing the deformation of the shadow produced by the black hole parameters with the observed deviation from circularity and the angular deviation from the M 87 ∗ data.