Self-gravitating system made of axions

TL;DR

This paper investigates how axion-like particles influence the properties of self-gravitating scalar systems, revealing they could form tiny, asteroid-sized objects that mimic dark matter halos.

Contribution

It introduces the impact of axion-like potentials on self-gravitating scalar systems and computes their mass and radius using current axion parameters.

Findings

Axion potentials decrease system compactness with higher self-interaction

Objects have asteroid-scale masses and meters-scale radii

Potential role as scalar mini-macho dark matter candidates

Abstract

We show that the inclusion of an axion-like effective potential in the construction of a self-gravitating system made of scalar fields leads to a decrease on its compactness when the value of the self-interaction coupling constant is increased. By including the current values for the axion mass m and decay constant f_a, we have computed the mass and the radius for self-gravitating systems made of axion particles. It is found that such objects will have asteroid-size masses and radius of few meters, then, the self-gravitating system made of axions could play the role of scalar mini-machos that are mimicking a cold dark matter model for the galactic halo.