Boson stars are theoretical celestial objects composed of bosons, which are one of the fundamental types of particles, alongside fermions. Unlike fermions, which make up matter in more familiar forms such as protons and neutrons, bosons are typically force carriers—such as photons and gluons—or, in speculative theories, may include hypothesized particles like axions.
Boson stars are unique because they represent a form of exotic matter that can exist under entirely different physical laws than those of conventional stars composed of fermions. They do not emit light, making them invisible and challenging to detect with existing astronomical techniques. Their existence is hypothesized primarily through the implications of quantum field theories and high-energy physics.
The connection between boson stars and dark matter lies in the hunt to identify the mysterious substance that makes up about 27% of the universe’s mass-energy content. Dark matter is known to exert gravitational effects, such as influencing the rotational speeds of galaxies and bending light from distant objects—a phenomenon known as gravitational lensing—but its composition remains unknown.
Some theoretical physicists propose that dark matter could partially or entirely be composed of bosonic particles, leading to the possibility that boson stars are a substantial component of dark matter. If boson stars exist and are abundant, they could constitute a significant fraction of the dark matter in the universe, explaining some of the gravitational effects attributed to dark matter without requiring new particles beyond the standard model of particle physics.
Understanding boson stars and their properties could offer critical insights into both high-energy physics and cosmology, potentially revealing aspects of the universe that are hidden beyond the reach of conventional astrophysical observations. Research in this field continues, using both theoretical models and searching for indirect evidence through astronomical observations and experiments designed to detect particles that might never have been observed before.