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E. J. Guerra (Rowan University), R. A. Daly (Penn State University)
Global cosmological parameters can be determined using sources observed over a range of redshift. These methods always involve a relation between observed and intrinsic source properties. For example, the peak luminosity of a type Ia supernova is predicted using the rate of decline of the light curve, and the physical size of a FRIIb radio source is predicted using the radio surface brightness and apparent width of the source.
The relation between observed and intrinsic source properties may be derived from theoretical considerations, or may be deduced empirically. It will be shown that the way the relation is parameterized is of fundamental importance to the global cosmological parameters indicated by the method. And, it will be shown that using a relation determined empirically leads to substantially different results (well beyond the quoted uncertainties) from those obtained using a relation deduced from fundamental theoretical considerations. The implications of this result will be discussed.
This work was supported in part by the U.S. National Science Foundation.
The author(s) of this abstract have provided an email address for comments about the abstract: rdaly@psu.edu