A dark energy model alternative to generalized Chaplygin gas

Abstract

By proposing a new cosmic fluid model of [Formula: see text] as an alternative to the generalized Chaplygin gas, we reexamine the role of Chaplygin gaslike fluid models in understanding dark energy and dark matter. Instead of as a unified dark matter, the fluid is suggested to be a mixture of unclustered dark energy and pressureless dark matter. Within such a scenario, the sub-horizon fluctuations of matter are stable and scale invariant, similar to those in standard [Formula: see text] model.