Testing Cosmological Models and Understanding Cosmological Parameter Determinations with Metaparameters

Cosmological parameters affect observables in physically distinct ways. For example, the baryon density, ωb, affects the ionization history and also the pressure of the pre-recombination fluid. To investigate the relative importance of different physical effects to the determination of ωb, and to test the cosmological model, we artificially split ωb into two ‘metaparameters’: ωbe which controls the ionization history and ωbp which plays the role of ωb for everything else. In our demonstration of the technique we find ωb = .0229± .0012 (with no parameter splitting), ωbp = .0238± .0021,ωbe = .0150± .0034 and ωbp −ωbe = .0088± .0039. Subject headings: cosmology: theory – cosmology: observation