Abstract
The estimation of cosmological parameters from a given data set requires a construction of a likelihood function which, in general, has a complicated functional form. We adopt a Gaussian copula and constructed a copula likelihood function for the convergence power spectrum from a weak lensing survey. We show that the parameter estimation based on the Gaussian likelihood erroneously introduces a systematic shift in the confidence region, in particular, for a parameter of the dark energy equation of state . Thus, the copula likelihood should be used in future cosmological observations.
- Received 11 August 2010
DOI:https://doi.org/10.1103/PhysRevLett.105.251301
© 2010 The American Physical Society