Scientific article
Open access

Conformal symmetries of FRW accelerating cosmologies

Published inNuclear physics. B, vol. 884, p. 547-565
  • Open Access - SCOAP3
Publication date2014

We show that any accelerating Friedmann–Robertson–Walker (FRW) cosmology with equation of state w<−1/3 (and therefore not only a de Sitter stage with w=−1) exhibits three-dimensional conformal symmetry on future constant-time hypersurfaces if the bulk theory is invariant under bulk conformal Killing vectors. We also offer an alternative derivation of this result in terms of conformal Killing vectors and show that long wavelength comoving curvature perturbations of the perturbed FRW metric are just conformal Killing motions of the FRW background. We then extend the boundary conformal symmetry to the bulk for accelerating cosmologies. Our findings indicate that one can easily generate perturbations of scalar fields which are not only scale invariant, but also fully conformally invariant on super-Hubble scales. Measuring a scale-invariant power spectrum for the cosmological perturbation does not automatically imply that the universe went through a de Sitter stage.

Citation (ISO format)
KECHAGIAS, Alexandros, RIOTTO, Antonio Walter. Conformal symmetries of FRW accelerating cosmologies. In: Nuclear physics. B, 2014, vol. 884, p. 547–565. doi: 10.1016/j.nuclphysb.2014.05.006
Main files (1)
Article (Published version)
ISSN of the journal0550-3213

Technical informations

Creation10/03/2014 2:21:00 PM
First validation10/03/2014 2:21:00 PM
Update time03/14/2023 9:49:15 PM
Status update03/14/2023 9:49:14 PM
Last indexation02/12/2024 11:19:31 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack