• cosmological parameters;
  • cosmology: observations;
  • cosmology: theory


The Fractal Bubble model has been proposed as a viable cosmology that does not require dark energy to account for cosmic acceleration, but rather attributes its observational signature to the formation of structure. In this Letter, it is demonstrated that, in contrast to previous findings, this model is not a good fit to cosmological supernovae data; there is significant tension in the best-fitting parameters obtained from different samples, whereas Λcold dark matter (ΛCDM) is able to fit all data sets consistently. Furthermore, the concordance between galaxy-clustering scales and data from the cosmic microwave background is not achieved with the most recent supernova compilations. The validity of the Fractal Bubble formalism as a sound cosmological model is further challenged as it is shown that previous studies of this model achieve concordance by requiring a value for the present-day Hubble constant that is derived from supernovae data containing an arbitrary distance normalization.