Non-relativistic Boson Stars as N-Body Quantum Systems

TL;DR

This paper investigates the structure of non-relativistic boson stars modeled as Bose-Einstein condensates, showing how their properties can be derived from single-particle behavior and comparing different ansatz-based models for equilibrium configurations.

Contribution

It introduces a method to analyze boson star structures using single-particle properties and compares multiple ansatz models to understand their equilibrium states.

Findings

Different ansatz models predict similar equilibrium configurations.

Boson stars can range from star-sized to galaxy cluster scales.

Harmonic oscillator approximation helps describe equilibrium conditions.

Abstract

In the present work, we analyze the structural configuration of a collection of generic non-relativistic bosons forming a gravitational bound Bose-Einstein condensate that we interpreted as a non-relativistic boson star. We prove that the system's behavior can be obtained by analyzing its fundamental constituent's properties, i.e., the single particle properties. Additionally, we show that by expressing the corresponding Newtonian gravitational potential, under certain circumstances, as a harmonic oscillator potential ones, we can describe the conditions in which the non-relativistic boson star can form equilibrium configurations. In order to analyze the structural configuration related to the boson star, we employ four different \textit{ans\"atze} commonly used in the literature. The use of these \textit{ans\"atze} allows to compare the structural properties of the bosonic cloud or the boson star that leads to obtain several equilibrium configurations from compact objets matching to the size of typical stars to very gigantic systems comparable to the size of galaxy cluster dark matter halos. Finally, we show that these \textit{ans\"atze} predict, qualitatively speaking, the same structural and gravitational equilibrium configurations for different values of the parameters involved.