The Trouble with Hubble: Local versus Global Expansion Rates in Inhomogeneous Cosmological Simulations with Numerical Relativity

Hayley J. Macpherson, Paul D. Lasky, Daniel J. Price

Research output: Contribution to journalArticleResearchpeer-review

31 Citations (Scopus)


In a fully inhomogeneous, anisotropic cosmological simulation performed by solving Einstein's equations with numerical relativity, we find that a local measurement of the effective Hubble parameter differs by less than 1% compared to the global value. This variance is consistent with predictions from Newtonian gravity. We analyze the averaged local expansion rate on scales comparable to Type 1a supernova surveys, and find that local variance cannot resolve the tension between the Riess et al. and Planck Collaboration et al. measurements.

Original languageEnglish
Article numberL4
Pages (from-to)1-6
Number of pages6
JournalThe Astrophysical Journal Letters
Issue number1
Publication statusPublished - 20 Sept 2018


  • cosmology: theory
  • gravitation
  • large-scale structure of universe

Cite this