Year: 2013
Type: article
Abstract: For decades, H 0 and q 0 were the quest of cosmology, as they promised to characterize our "world model" without reference to a specific cosmological framework. Using Monte Carlo simulations, we show that q 0 cannot be directly measured using distance indicators with both accuracy (without offset away from its true value) and precision (small error bar). While H 0 can be measured with accuracy and precision, to avoid a small bias in its direct measurement (of order 5%) we demonstrate that the pair H 0 and Ω M (assuming flatness and w = −1) is a better choice of two parameters, even if our world model is not precisely ΛCDM. We illustrate this with analysis of the Constitution set of supernovae and indirectly infer q 0 = −0.57 ± −0.04. Finally, we show that it may be possible to directly determine q 0 with both accuracy and precision using the time dependence of redshifts ("redshift drift").
Source: The Astrophysical Journal
Authors: Abraham R. Neben, Michael S. Turner
Institutions: Massachusetts Institute of Technology, University of Chicago
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2949795107