Testing cosmological models and understanding cosmological parameter determinations with metaparameters

Cosmological parameters affect observables in physically distinct ways. For example, the baryon density omega(b) 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 omega(b) and to test the cosmological model, we artificially split omega(b) into two "metaparameters'': omega(be), which controls the ionization history, and omega(bp), which plays the role of omega(b) for everything else. In our demonstration of the technique we find omega(b) = 0.0229+/-0.0012 (with no parameter splitting), omega(bp) = 0.0238+/-0.0021, omega(be) = 0/0238+/-0.0021, omega(be) = 0.0150+/-0.0034, and omega(bp)-omega(be) = 0.0088+/-0.0039.