Understanding Boson Stars as Potential Dark Matter Candidates

[wolram]

Boson stars seem to be a good fit for Dark Matter.
https://arxiv.org/pdf/1704.05057v1.pdf
Can you help me understand why such a huge particle with such low mass can exist, and how it could be found experimentally.

 

[PeterDonis]

Moderator's note: moving to the Beyond the Standard Model forum as the question is really about a hypothesized particle species not in the SM.

 

[Demystifier]

Boson stars seem to be a good fit for Dark Matter.
https://arxiv.org/pdf/1704.05057v1.pdf
Can you help me understand why such a huge particle with such low mass can exist, and how it could be found experimentally.

Boson star is a solitonic solution of classical nonlinear field equations. As such, it consists of many elementary particles, or more precisely it is a quantum coherent state in which the number of particles is uncertain. The mass is low because there is an attractive force which makes a negative contribution to the total energy.

 

[wolram]

So it is a BEC, why is it it can not be seen against CBR?

 

[kimbyd]

So it is a BEC, why is it it can not be seen against CBR?

The "boson stars" are basically just cold dark matter. Each "star" is a galactic halo, each of which is much larger than a visible galaxy. The concept here is that low-mass particles make up the dark matter, and they condense to form Bose-Einstein condensates in galaxy halos. Low-mass dark matter candidates are produced in ways that ensure they have very little kinetic energy, and the leading candidate is the axion.

The way they would be detected would be by detecting the low-mass particles that make them up. This tends to be much more difficult than it is for WIMPs (which have much higher masses), but there have been some attempts (e.g. https://en.wikipedia.org/wiki/Axion_Dark_Matter_Experiment).

Edit: And yes, these candidates are perfectly compatible with the CMB, as they are a potential theoretical explanation for cold dark matter which fits the CMB data quite well.

 

[wolram]

Thank you very much for the answers to my questions