Expansion, geometry, and gravity

  title={Expansion, geometry, and gravity},
  author={Robert R. Caldwell and Marc Kamionkowski},
  journal={Journal of Cosmology and Astroparticle Physics},
In general-relativistic cosmological models, the expansion history, matter content, and geometry are closely intertwined. In this brief paper, we clarify the distinction between the effects of geometry and expansion history on the luminosity distance. We show that the cubic correction to the Hubble law, measured recently with high-redshift supernovae, is the first cosmological measurement, apart from the cosmic microwave background, that probes directly the effects of spatial curvature. We… Expand

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