Abstract
Cosmological observations suggest the existence of two different kinds of energy densities dominating at small and large scales. The dark matter component, which dominates at small scales, contributes and has an equation of state while the dark energy component, which dominates at large scales, contributes and has an equation of state It is usual to postulate weakly interacting massive particles (WIMPs) for the first component and some form of scalar field or cosmological constant for the second component. We explore the possibility of a scalar field with a Lagrangian acting as both clustered dark matter and smoother dark energy and having a scale-dependent equation of state. This model predicts a relation between the ratio of the energy densities of the two dark components and an expansion rate n of the universe [with in the form For we get which is consistent with observations.
- Received 8 May 2002
DOI:https://doi.org/10.1103/PhysRevD.66.081301
©2002 American Physical Society