English

Dark Matter Superfluidity

Cosmology and Nongalactic Astrophysics 2022-03-16 v2 High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

In these lectures I describe a theory of dark matter superfluidity developed in the last few years. The dark matter particles are axion-like, with masses of order eV. They Bose-Einstein condense into a superfluid phase in the central regions of galaxy halos. The superfluid phonon excitations in turn couple to baryons and mediate a long-range force (beyond Newtonian gravity). For a suitable choice of the superfluid equation of state, this force reproduces the various galactic scaling relations embodied in Milgrom's law. Thus the dark matter and modified gravity phenomena represent different phases of a single underlying substance, unified through the rich and well-studied physics of superfluidity.

Keywords

Cite

@article{arxiv.2109.10928,
  title  = {Dark Matter Superfluidity},
  author = {Justin Khoury},
  journal= {arXiv preprint arXiv:2109.10928},
  year   = {2022}
}

Comments

21 pages, 1 figure, Submitted to SciPost Physics Lecture Notes, Les Houches Summer School Series. v2: corrected typos and added references

R2 v1 2026-06-24T06:13:46.472Z