Global monopole in a Ricci-coupled Kalb-Ramond bumblebee gravity

TL;DR

This paper explores new black hole solutions in a modified gravity theory that includes Lorentz symmetry breaking and a global monopole, analyzing their observational signatures and constraining model parameters with solar system data.

Contribution

It introduces novel black hole solutions in Einstein-Kalb-Ramond bumblebee gravity with a global monopole and Lorentz symmetry breaking, and assesses their observational implications.

Findings

Derived new black hole solutions with LSB and monopole effects.

Constrained monopole charge $\

Estimated upper bounds for the monopole charge $\

Abstract

In this paper, we investigate black hole solutions in Einstein-Kalb-Ramond (EKR) bumblebee gravity sourced by a global monopole characterized by the charge $\eta$. This modified theory of gravity possesses the notable feature of incorporating local Lorentz symmetry breaking (LSB) via a spontaneous symmetry-breaking mechanism. We solve the field equations for a static and spherically symmetric metric with the Kalb-Ramond (KR) field fixed at its VEV, thereby obtaining new black hole solutions. These solutions simultaneously exhibit the LSB effects, codified by the $\gamma$ parameter, and the global monopole effects, codified by the charge $\eta$. Next, we study the impact of the global monopole and LSB corrections on two classical tests, namely, the advance of Mercury's perihelion and the light deflection. Furthermore, we compute the Hawking temperature, black hole shadows, and greybody factors. Ultimately, we estimate an upper bound for $\eta$ by comparing the theoretical results provided by the EKR model with observational data from the advance of Mercury's perihelion and light deflection.