Perturbative effective field theory at finite density

An accurate description of nuclear matter starting from free-space nuclear forces has been an elusive goal. The complexity of the system makes approximations inevitable, so the challenge is to find a consistent truncation scheme with controlled errors. Non-perturbative effective field theories could be well suited for the task. Perturbative matching in a model calculation is used to explore some of the issues encountered in extending effective field theory techniques to many-body calculations.