Parameterizing the Deceleration Parameter
  We propose and constrain with the latest observational data three parameterizations of the deceleration parameter, valid from the matter era to the far future. They are well behaved and do not diverge at any redshift. On the other hand, they are model independent in the sense that in constructing them the only assumption made was that the Universe is homogeneous and isotropic at large scales. 
Diego Pav\'on, Ivan Duran, Sergio del Campo and Ram\'on Herrera
gr-qc