# Ultralight bosonic dark matter in white dwarfs and potential observational consequences

**Authors:** Nicolas Sanchis-Gual, Paula Izquierdo  
**arXiv:** [2202.00434](https://arxiv.org/abs/2202.00434)  
**Date:** 2022-02-01  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2202.00434v1/

## Key points

- Study investigates interaction between fluid and ultralight bosonic dark matter through gravity
- Authors explore formation of stable fermion-boson stars
- Focus on dynamical formation of a spherical mixed white-dwarf--boson star undergoing gravitational cooling
- Properties of object depend on mass of boson particle and mass of boson star itself
- Accreting bosonic dark matter transforms white dwarf into denser and more compact object with core composed of a boson star
- Transformation leads to modifications in gravitational redshift and electromagnetic radiation emitted from photosphere
- Changes in gravitational redshift can introduce small discrepancies in estimating masses and radii derived from observations of white dwarfs
- Research sheds light on how ultralight bosonic dark matter affects white dwarfs and provides insights into potential observational consequences
- Work expands understanding of astrophysical phenomena and contributes to ongoing efforts to uncover the nature of dark matter

## Summary

In their study titled "Ultralight bosonic dark matter in white dwarfs and potential observational consequences," authors Nicolas Sanchis-Gual and Paula Izquierdo investigate the interaction between fluid and ultralight bosonic dark matter through gravity. They explore the formation of stable fermion-boson stars, which are static and regular mixed solutions of the Einstein-Euler-(complex, massive) Klein-Gordon system. Specifically focusing on the dynamical formation of a spherical mixed white-dwarf--boson star undergoing gravitational cooling, they examine how the properties of this object depend on both the mass of the boson particle and the mass of the boson star itself. As a result of accreting bosonic dark matter, the white dwarf transitions into a denser and more compact object with a core composed of a boson star. This transformation leads to modifications in various aspects of the white dwarf, including its gravitational redshift and electromagnetic radiation emitted from its photosphere. These changes in gravitational redshift caused by any type of dark matter can potentially introduce small discrepancies in estimating masses and radii derived from observations of white dwarfs. Through their research on these implications, Sanchis-Gual and Izquierdo shed light on how ultralight bosonic dark matter can affect white dwarfs and provide valuable insights into potential observational consequences. Their work expands our understanding of these astrophysical phenomena and contributes to ongoing efforts to uncover the nature of dark matter.