Testing the concordance model in cosmology with model-independent   methods: some issues
  Since the number of dark energy models have rapidly increased over the last years, some model-independent methods have been developed in order to analyse the cosmological evolution in a phenomenological way. In this manuscript, we analyse some of these approaches and their shortcomings to provide reliable information. 
Diego Saez-Gomez (IA, U. of Lisbon)
gr-qc astro-ph.CO