Can a multiverse theory explain the H_0 tension, the S_8 tension, the w(z) < -1 behavior and many other cosmological observations? Maybe!

April 30, 2026 PIRSA:26040130 Scientific Series Quantum Gravity

Ambjorn, J. (2026). Can a multiverse theory explain the H_0 tension, the S_8 tension, the w(z) < -1 behavior and many other cosmological observations? Maybe!. Perimeter Institute. https://pirsa.org/26040130

Ambjorn, Jan. Can a multiverse theory explain the H_0 tension, the S_8 tension, the w(z) < -1 behavior and many other cosmological observations? Maybe!. Perimeter Institute, Apr. 30, 2026, https://pirsa.org/26040130

@misc{ pirsa_PIRSA:26040130,
  doi = {10.48660/26040130},
  url = {https://pirsa.org/26040130},
  author = {Ambjorn, Jan},
  keywords = {Quantum Gravity},
  language = {en},
  title = {Can a multiverse theory explain the H_0 tension, the S_8 tension, the w(z) < -1 behavior and many other cosmological observations? Maybe!},
  publisher = {Perimeter Institute},
  year = {2026},
  month = {apr},
  note = {PIRSA:26040130 see, \url{https://pirsa.org}}
}

Abstract

A simple multiverse model explains the late time exponential expansion of our universe without the need of a cosmological constant. Assuming that the local measurement of H_0 is correct, it also give a better fit to data than the standard LCDM model, as well as a z-dependent state parameter w(z) that is not incompatible with the latest DESI data. An (tentative) underlying microscopic theory of the multiverse model, based on W_3 and exceptional Jordan algebras may allow us to calculate the expansion rate of our universe.