In this paper I discuss what we truly know about dark energy. I shall argue that up to date our single indication for the existence of dark energy comes from distance measurements and their relation to redshift. Supernovae, CMB anisotropies and observations of baryon acoustic oscillations, they all simply tell us that the observed distance to a given redshift is larger than the one expected from a Friedmann Lemaitre universe with matter only and the locally measured Hubble parameter.
Philosophical Transactions of the Royal Society of London Series A
- Pub Date:
- December 2011
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology
- invited talk at the meeting "Cosmological Tests of General Relativity" at the Kavli Royal Society Center for the Advancement of Science organized by Rachel Bean, Pedro Ferreira and Andy Taylor. 14p 2 figs. revised version: updated to match version in print in Phil. Trans. R. Soc. A