Matter accretion onto charged black holes in symmergent gravity

Abstract

In astrophysics, accretion is a process where the black hole acquires matter. The gravitational energy is released as a result of the accretion and converted into radiation. Accretion onto dark compact objects, for example, neutron stars, white dwarfs, and black holes is a significant process in the astrophysical phenomenon. It is a fruitful way to examine the features of modified gravity theories by testing the analysis of their results related to dark compact objects. Here, we study the motion of a charged particle moving in near a charged symmergent black hole with Maxwell field. The symmergent gravity is a newly developed modified theory gravity within the framework of the vacuum energy VO, gravitational constant G, and quadratic curvature coefficient cO. The vacuum energy VO can be defined in terms of G and cO in the case where all the fields are degenerate in the form of mass. Further, two different choices of the parameter α provide us two different black hole spacetimes, like de Sitter for α<1 and anti-de Sitter for α>1. For this, we explore the accretion of perfect fluid onto the spherically symmetric charged symmergent black hole. Then, we get analytical results among the four-velocity and energy densities of the accreting matter. Further, we investigate it for well-known fluids flowing onto a charged symmergent black hole. Applying the Hamiltonian approach, we are able to explore the nature of accretion for these fluids such as ultra-stiff fluid, ultra-relativistic fluid, radiation fluid, and sub-relativistic fluid onto the source mass. For this study, we classified isothermal types of fluid in the context of equations of state. In addition, we introduced the application of polytropic test fluid associated with accretion disks. The accretion rate is analyzed near a charged symmergent black hole, which produced a typical behavior presented graphically by the significant parameters α and Q.