Backreaction inhomogeneities in the cosmological parameter evolution via a noncommutative fluid

The paper discusses backreaction effects in cosmology, (a la Buchert et al.), induced by noncommutative geometry effects in fluid. We have used generalizations of an action formulation of a noncommutative fluid model proposed earlier by us. We show that the noncommutative effects, depending on their nature, can play either roles of (kinematical) dark matter or cosmological constant.