Neutron star structure in a quark model with excluded volume correction
  We study the effects of the finite size of baryons on the equation of state of homogeneous hadronic matter. The finite extension of hadrons is introduced in order to improve the performance of field theoretical models at very high densities. We simulate the in-medium averaged baryon-baryon strong repulsion at very short distances by introducing a Van der Waals like normalization of the fields. This is done in the framework of the Quark Meson Coupling model, that allows to take care of the quark structure of baryons. Since within this model the confinement volume evolves with the fields configuration, the treatment is not equivalent to a simple hard-core potential. We investigate the phase transition to quark matter and the structure of neutron stars. We have found significant corrections at high densities. 
R.M. Aguirre and A.L. De Paoli