Low density nuclear matter in effective field theory

The two- and three-nucleon interaction derived in chiral effective field theory is used to obtain the binding energy of nuclear matter for small densities at next-to-leading (NLO) and next-to-next-to-leading orders (N2LO). The order N2LO is not yet sufficient to push the range of validity of the expansion beyond the empirical Fermi momentum of nuclear matter. A phenomenological extension of the interaction suggests that both effective three- and four-nucleon interactions are required for a description of the bulk properties of nuclear mater.