Two-fluid dark matter models

Understand

We investigate the possibility that dark matter is a mixture of two non-interacting perfect fluids, with different four-velocities and thermodynamic parameters.

• The two-fluid model can be described as an effective single anisotropic fluid, with distinct radial and tangential pressures.
• The basic equations describing the equilibrium structure of the two-fluid dark matter model, and of the tangential velocity of test particles in stable circular orbits, are obtained for the case of a spherically symmetric static geometry.
• By assuming a non-relativistic kinetic model for the dark matter particles, the density profile and the tangential velocity of the dark matter mixture are obtained by numerically integrating the gravitational field equations.