The neutrino pair annihilation ($\nu\bar{\nu}\longrightarrow e^{-}e^{+}$)around a massive source with an $f(R)$ global monopole

TL;DR

This paper studies how $f(R)$ gravity and global monopoles influence neutrino pair annihilation energy deposition, suggesting these effects could explain gamma-ray bursts and be observable astrophysically.

Contribution

It introduces a model combining $f(R)$ gravity and global monopoles to analyze neutrino annihilation, highlighting their impact on energy release and gamma-ray bursts.

Findings

Greater deviation from general relativity increases energy deposition ratio.

Global monopoles significantly enhance the energy release, potentially causing heavier gamma-ray bursts.

The model parameters can be tuned to match astronomical observations.

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 $\frac{\dot{Q}}{\dot{Q_{Newt}}}$ meaning that the energy deposition per unit time is over that in the Newtonian case. It is found that the more deviation from general relativity leads more energy to set free from the annihilation with greater ratio value. It should also be pointed out that the existence of global monopole makes a sharp increase in the ratio $\frac{\dot{Q}}{\dot{Q_{Newt}}}$, causing heavier gamma-ray burst. We also discuss the derivative $\frac{d\dot{Q}}{dr}$ as a function of radius $r$ of star to show the similar characters that the considerable modification of Einstein's gravity and the global monopole with unified theory order will raise the amount of $\frac{d\dot{Q}}{dr}$ 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 $\psi_{0}$ to be comparable with the accelerating universe while regulate the parameter $\eta$ for the global monopole in order to make the ratio curves to coincide with the results from astronomy. It is possible to probe the monopole from astrophysical observations.