Cosmographic analysis of dark energy

Understand

The Hubble relation between distance and redshift is a purely cosmographic relation that depends only on the symmetries of a FLRW spacetime, but does not intrinsically make any dynamical assumptions.

• This suggests that it should be possible to estimate the parameters defining the Hubble relation without making any dynamical assumptions.
• To test this idea, we perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets, paying careful attention to the systematic uncertainties.
• Based on this supernova data, the "preponderance of evidence" certainly suggests an accelerating universe.