New insights into the formation and growth of boson stars in dark matter halos

TL;DR

This paper investigates the formation, growth, and stability of boson stars within dark matter halos, considering gravitational effects and both attractive and repulsive self-interactions through advanced numerical simulations.

Contribution

It provides the first dynamical analysis of boson star growth with self-interactions, revealing conditions for stability, collapse, and fragmentation.

Findings

Boson star growth saturates inside halos under gravity.

Strong attractive self-interactions can cause collapse and fragmentation.

Repulsive self-interactions lead to larger, more stable boson stars.

Abstract

This work studies the formation and growth of boson stars and their surrounding miniclusters by gravitational condensation using non-linear dynamical numerical methods. Fully dynamical attractive and repulsive self-interactions are also considered for the first time. In the case of pure gravity, we numerically prove that the growth of boson stars inside halos slows down and saturates as has been previously conjectured, and detail its conditions. Self-interactions are included using the Gross-Pitaevskii-Poisson equations. We find that in the case of strong attractive self-interactions the boson stars can become unstable and collapse, in agreement with previous stationary computations. At even stronger coupling, the condensate fragments. Repulsive self-interactions, as expected, promote boson star formation, and lead to solutions with larger radii.