A novel black hole mimicker: a boson star and a global monopole nonminimally coupled to gravity

TL;DR

This paper introduces a composite boson star and global monopole system nonminimally coupled to gravity, which can mimic black holes by exhibiting high compactness without an event horizon.

Contribution

It presents a new field-theoretic model combining a boson star and a global monopole with nonminimal coupling, revealing regimes where the system mimics black hole properties.

Findings

Large energy density and pressures achieved

Configurations exhibit high compactness without horizons

Repulsive monopole stabilizes the boson star

Abstract

A field-theoretic model for a highly compact object that mimicks a black hole is found for the gravitationally interacting system of a boson star and a global monopole which are nonminimally coupled to gravity. According to the strength of the nonlinear gravitational effects and the gravitational backreaction, three distinct coupling regimes are featured: weak, mild and strong. In the strong coupling regime we show that a repulsive monopole stabilizes an attractive boson star and the resulting configuration exhibits large energy density, large (and negative) principal pressures, large compactness, large effective potential, large local forces, and yet exhibits no event horizon. As such a composite system of a boson star and a global monopole represents a convincing microscopic candidate for a black hole mimicker.