In today’s blog we talk to Dr. Roya Mohayaee, PhD from Imperial College London, and researcher at the Institut d’Astrophysique de Paris, on recent work that undermines evidence for cosmic acceleration and dark energy.
David: If the CMB and quasar frames are not close enough to each other, then the long-held assumption of homogeneity of the Universe on the largest scales, falls apart?
Roya: Yes, this is why we entitled our last paper, "a test of cosmological principle...". Cosmological principle is the assumption of large-scale homogeneity and isotropy. In our work, we are really testing the large-scale isotropy. In principle, one could still have homogeneity without isotropy but it is unlikely.
David: What do we make of the supernovae data? Is accelerated expansion called into question?
Roya: Yes, because in most of the analysis of supernova data, it is implicitly assumed that the Universe is isotropic and homogeneous on large scales (i.e. cosmological principle).
David: What reaction has this work triggered from the community?
Roya: Diverse reactions.... but it has surely triggered a lot of interest and scrutiny, which is rather positive. Our last paper on quasars has been taken seriously by established physicists, with whom we had many correspondences.
David: This is the latest in a series of papers on this topic that date back to 2016. Have other groups looked into the issues? Is anyone trying to reproduce your analysis?
Roya: Yes, our previous results on supernova and also on radio galaxies have been also confirmed by other groups (e.g; see the latest work by D. Schwarz group on radio galaxies)
The Cosmic Radio Dipole: Estimators and Frequency Dependence
David: Your work is referenced below. Thank you Dr. Mohayaee!
https://ui.adsabs.harvard.edu/abs/2020arXiv200914826S/abstract