On the Bondi accretion of a self-interacting complex scalar field
Abstract
Scalar fields with a global U(1) symmetry often appear in cosmology and astrophysics. We study the spherically-symmetric, stationary accretion of such a classical field onto a Schwarzschild black hole in the test-field approximation. Thus, we consider the relativistic Bondi accretion beyond a simplified perfect-fluid setup. We focus on the complex scalar field with canonical kinetic term and with a generic quartic potential which either preserves the U(1) symmetry or exhibits spontaneous symmetry breaking. It is well known that in the lowest order in gradient expansion the dynamics of such a scalar field is well approximated by a perfect superfluid; we demonstrate that going beyond this approximation systematically reduces the accretion rate with respect to the perfect fluid case. Hence, black holes can provide a way to distinguish a perfect fluid from its ultraviolet completion in form of the complex scalar field.
Cite
@article{arxiv.2511.04650,
title = {On the Bondi accretion of a self-interacting complex scalar field},
author = {Dražen Glavan and Alexander Vikman and Tom Zlosnik},
journal= {arXiv preprint arXiv:2511.04650},
year = {2026}
}
Comments
53 pages, 24 figures; discussion of P(X) limit and test field approximaiton expanded