Neutrino pair annihilation ($\nu{\bar \nu}\to e^-e^+$) in the presence of quintessence surrounding a black hole

TL;DR

This paper investigates how quintessence fields alter spacetime geometry around black holes, significantly increasing neutrino pair annihilation rates near the photon sphere, which could influence gamma-ray burst mechanisms.

Contribution

It introduces the impact of quintessence on neutrino annihilation near black holes, showing a substantial increase in energy deposition rates compared to standard General Relativity.

Findings

Energy deposition rate is several orders of magnitude higher with quintessence.

Quintessence increases the photon-sphere radius, affecting neutrino annihilation.

Results suggest a potential role in gamma-ray burst generation.

Abstract

Quintessence fields, introduced to explain the speed-up of the Universe, might affect the geometry of spacetime surrounding black holes, as compared to the standard Schwarzschild and Kerr geometries. In this framework, we study the neutrino pairs annihilation into electron-positron pairs ($\nu{\bar \nu}\to e^-e^+$) near the surface of a neutron star, focusing, in particular, on the Schwarzschild-like geometry in presence of quintessence fields. The effect of the latter is to increase the minimum photon-sphere radius ($R_{ph}$), increasing in such a way the maximum energy deposition rate near to $R_{ph}$. The rate turns out to be several orders of magnitude greater than the rate computed in the framework of General Relativity. These results might provide an efficient mechanism for the generation of GRBs and lead to constraints on the parameters of the quintessence model.