Testing the cosmological constant as a candidate for dark energy

Abstract

It is difficult to single out the best model of dark energy on the basis of the existing andplanned cosmological observations, because the parameter space of many different modelscan lead to similar observational consequences. However, each particular model can bestudied and either found consistent with observations or ruled out. In this paper, weconcentrate on the possibility of testing and ruling out the simplest and by farthe most popular of the models of dark energy, the theory described by generalrelativity with positive vacuum energy (the cosmological constant). We evaluate theconditions under which this model could be ruled out by future observationsmade by the Supernova/Acceleration Probe SNAP (both for supernovae andweak lensing) and by the Planck Surveyor cosmic microwave background satellite.