Spherical steady accretion flows -- dependence on the cosmological constant, exact isothermal solutions and applications to cosmology

Understand

We investigate spherical, isothermal and polytropic steady accretion models in the presence of the cosmological constant.

• Exact solutions are found for three classes of isothermal fluids, assuming the test gas approximation.
• The cosmological constant damps the mass accretion rate and - above certain limit - completely stops the steady accretion onto black holes.
• A "homoclinic-type" accretion flow of polytropic gas has been discovered in AdS spacetimes in the test-gas limit.