  A 1-parameter class of quadratic equations of state is confronted with the
Hubble diagram of supernovae. The fit is found to be as good as the one using
the standard LambdaCDM model. However this quadratic equation of state
precludes objects with redshifts higher than z_max = 1.7. Adding a fair amount
of cold baryons to the model increases z_max without spoiling the fit.
