Symbolic expressions for cosmic backreaction and mean redshift drift in a range of two-region models in terms of average quantities are presented. The demonstration that these expressions can be obtained constitutes the opening of a new avenue towards understanding the effects of cosmic backreaction in our universe: With a symbolic expression for the redshift drift at hand, the redshift drift can be used to constrain cosmological parameters including the large-scale expansion rate and backreaction. In addition, by introducing symbolic expressions for cosmic backreaction, this quantity can be constrained with observations such as redshift-distance measures.
- Received 24 February 2023
- Revised 31 March 2023
- Accepted 1 May 2023
© 2023 American Physical Society
Gravitation, Cosmology & Astrophysics