Non-parametric Dark Energy Degeneracies

We study the degeneracies between dark energy dynamics, dark matter and curvature using a nonparametric and non-perturbative approach. This allows us to examine the knock-on bias induced in the reconstructed dark energy equation of state, w(z), when there is a bias in the cosmic curvature or dark matter content, without relying on any specific parameterisation of w. Even assuming perfect Hubble, distance and volume measurements, we show that for z > 1, the bias in w(z) is up to two orders of magnitude larger than the corresponding errors in Ωk or Ωm. This highlights the importance of obtaining unbiased estimators of all cosmic parameters in the hunt for dark energy dynamics.