it depends upon the scale factor and hence upon the metric describing space-time.

Trajectories in the $s-r$ plane corresponding to different cosmological models exhibit qualitatively different behaviors. The spatially flat $\Lambda$CDM scenario corresponds to a fixed point in the diagram $$\{s,r\}\bigg\vert_{\rm \Lambda CDM} = \{ 0,1\} ~.\label{lcdm}$$ Departure of a given dark energy model from this fixed point provides a good way of establishing the “distance” of this model from $\Lambda$CDM [@sahni; @alam]. As demonstrated in Refs. [@sahni; @alam; @quintomsr; @gorini; @holosr; @zimdahl; @zx] the statefinder can successfully differentiate between a wide variety of dark energy models including the cosmological constant, quintessence, quintom, the Chaplygin gas, braneworld models, holographic dark energy and interacting dark energy models. We can clearly identify the “distance” from a given dark energy model to the $\Lambda$CDM scenario by using the $r(s)$ evolution diagram.

The current location of the parameters $s$ and $r$ in these diagrams can be calculated in models, and on the other hand it can also be extracted from data coming from SNAP (SuperNovae Acceleration Probe) type experiments [@sahni; @alam]. Therefore, the statefinder diagnostic combined with future SNAP observations may possibly be used to discriminate between different dark energy models. For example, as 