Recent progress with {\it ab initio} calculations of the nuclear equation of state

The properties of dense nuclear matter is a topic of current interest. More empirical information is becoming available through heavy-ion collision data and astrophysical observations, which can help set constraints on the equation of state (EOS) of nuclear matter in different density regions \footnote{T. Kl{\"a}hn {\it et al.}, Physical Review C {\bf 74}, 035802 (2006)}. In this contribution, I will present recent progress within the {\it ab initio} approach pursued by my group. Our goal is to gain a broad overview over nuclear matter properties, especially under the ``exotic" conditions of isospin and spin asymmetry. Moreover, the impact of non-nucleonic degrees of freedom on the EOS at higher densities will be discussed.