The neutrino pair annihilation around a massive source with an f(R) global monopole

Department of Physics, East China University of Science and Technology - Shanghai 200237, China and The Shanghai Key Laboratory of Astrophysics - Shanghai 200234, China

^(a) E-mail: hbcheng@ecust.edu.cn (corresponding author)

Received: 9 October 2022
Accepted: 7 November 2022

Abstract

In this work we investigate the neutrino pair annihilation around a gravitational object involving an f(R) global monopole. We derive and calculate the ratio meaning that the energy deposition per unit time is over that in the Newtonian case. It is found that the greater influence from f(R) theory leads more energy to set free from the annihilation with greater ratio value. It is important that the existence of global monopole makes a sharp increase in the ratio , causing heavier gamma-ray burst. We also discuss the derivative as a function of radius r of the star to show the similar features, that is the considerable modification of Einstein's gravity and the global monopole with unified theory order will raise the amount of more greatly. The stellar body with f(R) global monopole can be well qualified as a source of gamma-ray bursts. Moreover, we can select the factor to be comparable with the accelerating universe while regulating the parameter η for the global monopole in order to make the ratio curves coincide with the results from astronomy. It is possible to probe the monopole from astrophysical observations.