# Jerk, snap, and the cosmological equation of state

@article{Visser2003JerkSA, title={Jerk, snap, and the cosmological equation of state}, author={Matt Visser}, journal={Classical and Quantum Gravity}, year={2003}, volume={21}, pages={2603-2615} }

Taylor expanding the cosmological equation of state around the current epoch is the simplest model one can consider that does not make any a priori restrictions on the nature of the cosmological fluid. Most popular cosmological models attempt to be 'predictive', in the sense that once some a priori equation of state is chosen the Friedmann equations are used to determine the evolution of the FRW scale factor a(t). In contrast, a 'retrodictive' approach might usefully take observational data…

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