# Dynamical evolution of boson stars in Brans-Dicke theory

**Authors:** Jayashree Balakrishna, Hisa-aki Shinkai  
**arXiv:** [gr-qc/9712065](https://arxiv.org/abs/gr-qc/9712065)  
**Date:** 1997-12-15  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/gr-qc--9712065v2/

## Key points

- Jayashree Balakrishna and Hisa-aki Shinkai investigate the dynamics of a self-gravitating scalar field solitonic object known as a boson star in the context of the Jordan-Brans-Dicke (BD) theory of gravity.
- The authors explore various dynamical processes within this system, including the formation of black holes from perturbed equilibrium configurations on an unstable branch and the migration of these perturbed configurations to a stable branch.
- They also examine the transition from an excited state to a ground state.
- Boson stars in BD theory behave similarly to those in general relativity (GR), emitting comparable levels of scalar waves.
- This suggests that boson stars can form in BD theory much like they do in GR.
- Balakrishna and Shinkai demonstrate the formation of a stable boson star using initial data consisting of a Gaussian scalar field packet with flat gravitational scalar field characteristics.
- This experiment strengthens their conclusion that boson stars can be generated within BD theory through similar mechanisms as those operating in GR.
- The study provides valuable insights into the dynamics and formation processes of boson stars within alternative theories of gravity such as BD theory.
- By highlighting similarities between BD theory and GR, it contributes to our understanding of how these exotic objects can arise and evolve under different gravitational frameworks.

## Summary

In their study, Jayashree Balakrishna and Hisa-aki Shinkai investigate the dynamics of a self-gravitating scalar field solitonic object known as a boson star in the context of the Jordan-Brans-Dicke (BD) theory of gravity. The authors explore various dynamical processes that occur within this system, including the formation of black holes from perturbed equilibrium configurations on an unstable branch and the migration of these perturbed configurations from the unstable branch to a stable branch. They also examine the transition from an excited state to a ground state. The researchers find that boson stars in BD theory behave similarly to those in general relativity (GR), emitting comparable levels of scalar waves. This suggests that despite differences in underlying theories, boson stars can form in BD theory much like they do in GR. To support their findings, Balakrishna and Shinkai demonstrate the formation of a stable boson star using initial data consisting of a Gaussian scalar field packet with flat gravitational scalar field characteristics. This experiment further strengthens their conclusion that boson stars can indeed be generated within BD theory through similar mechanisms as those operating in GR. Overall, this study provides valuable insights into the dynamics and formation processes of boson stars within alternative theories of gravity such as BD theory. By highlighting similarities between BD theory and GR, it contributes to our understanding of how these exotic objects can arise and evolve under different gravitational frameworks.