Spontaneous Lorentz symmetry breaking effects on GRBs jets arising from neutrino pair annihilation process near a black hole

Abstract

The study of neutrino pair annihilation into electron-positron pairs ($$\nu {\bar{\nu }}\rightarrow e^-e^+$$ ν ν ¯ → e - e + ) is astrophysically well-motivated because it is a possible powering mechanism for the gamma-ray bursts (GRBs). In this paper, we estimate the gamma-ray energy deposition rate (EDR) arising from the annihilation of the neutrino pairs in the equatorial plane of a slowly rotating black hole geometry modified by the broken Lorentz symmetry (induced by a background bumblebee vector field). More specifically, owing to the presence of a dimensionless Lorentz symmetry breaking (LSB) parameter l arising from nonminimal coupling between the bumblebee field with nonzero vacuum expectation value and gravity, the metric solution in question differs from the standard slowly rotating Kerr black hole. By idealizing the thin accretion disk temperature profile in the two forms of isothermal and gradient around the bumblebee gravity-based slow rotating black hole, we investigate the influence of spontaneous LSB on the $$\nu {\bar{\nu }}$$ ν ν ¯ -annihilation efficiency. For both profiles, we find that positive values of LSB parameter $$l>0$$ l > 0 induce an enhancement of the EDR associated with the neutrino-antineutrino annihilation. Therefore, the process of powering the GRBs jets around bumblebee gravity modified slowly rotating geometry is more efficient in comparison with standard metric. Using the observed gamma-ray luminosity associated with different GRBs types (short, long, and ultra-long), we find, through the analysis of the EDR in the parameter space $$l-a$$ l - a ($$a^2\ll 1$$ a 2 ≪ 1 ), some allowed ranges for the LSB parameter l.

Influence of plasma on the optical appearance of spinning black hole in Kalb-Ramond gravity and its Existence around M87* and Sgr A*

“…He found when the BH is surrounded by a plasma region with a weak magnetization, the energy extraction due to magnetic reconnection increases for negative values of LSB parameter. Khodadi et al [21] explored the rate of energy deposition for gamma-rays induced by the annihilation of neutrino pairs for a slowly rotating BH, with modifications due to spontaneous LSB, specifically considering the plane passing through the equator. It was found that the energy deposition rate is increased for positive values of LSB parameter.…”

Dark matter spike around Bumblebee black holes

“…in the region where the DM density is high), using the so-called Bumblebee Gravity model. This model extends the standard framework of GR and allows for spontaneous Lorentz symmetry breaking through a non-zero vacuum expectation value of the bumblebee vector field B µ under a suitable potential [60,61]. The bumblebee model is an example of a theory that exhibits Lorentz violation arising from a single vector B µ that acquires a non-zero vacuum expectation value, and it is among the simplest field theories with spontaneous Lorentz and diffeomorphism violations [62][63][64][65][66][67].…”

Spontaneous and Explicit Spacetime Symmetry Breaking in Einstein–Cartan Theory with Background Fields

“…These different frameworks have been used to analyze a wide range of experimental tests of spacetime symmetry in gravity theories [25]. In addition, specific models exhibiting spontaneous spacetime symmetry have been constructed and investigated [15,16,29,30], including Bumblebee models, where numerous applications have been explored (for examples, see [122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137]).…”