Accretion of Ghost Condensate by Black Holes

TL;DR

This paper demonstrates that ghost condensate can be accreted by black holes at extremely high rates, which imposes strong constraints on ghost condensate models due to potential rapid black hole growth.

Contribution

It provides a detailed analysis of steady-state accretion of ghost condensate onto black holes, highlighting the efficiency and implications for theoretical models.

Findings

Accretion rate can reach up to a tenth of a solar mass per second.

Accretion rate depends on the energy scale of the ghost condensate, not cosmological density.

High accretion rates impose constraints on ghost condensate parameters.

Abstract

The intent of this letter is to point out that the accretion of a ghost condensate by black holes could be extremely efficient. We analyze steady-state spherically symmetric flows of the ghost fluid in the gravitational field of a Schwarzschild black hole and calculate the accretion rate. Unlike minimally coupled scalar field or quintessence, the accretion rate is set not by the cosmological energy density of the field, but by the energy scale of the ghost condensate theory. If hydrodynamical flow is established, it could be as high as tenth of a solar mass per second for 10MeV-scale ghost condensate accreting onto a stellar-sized black hole, which puts serious constraints on the parameters of the ghost condensate model.