Statefinder: A New geometrical diagnostic of dark energy
Jan, 2002
6 pages
Published in:
- JETP Lett. 77 (2003) 201-206,
- Pisma Zh.Eksp.Teor.Fiz. 77 (2003) 249-253
e-Print:
- astro-ph/0201498 [astro-ph]
DOI:
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Abstract: (arXiv)
We introduce a new cosmological diagnostic pair called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters and , is constructed from the scale factor of the Universe and its derivatives only. The parameter forms the next step in the hierarchy of geometrical cosmological parameters used to study the Universe after and , while the parameter is a linear combination of and chosen in such a way that it does not depend upon the dark energy density . The Statefinder pair is algebraically related to the the dark energy pressure-to-energy ratio and its time derivative, and sheds light on the nature of dark energy/quintessence. Its properties allow to usefully differentiate between different forms of dark energy with constant and variable , including a cosmological constant (). The Statefinder pair can be determined to very good accuracy from a SNAP type experiment.Note:
- 7 pages, 3 figures. Final version to be published in JETP Lett., presentation shortened, references added and updated, consideration of brane cosmological models included, conclusions unchanged
References(29)
Figures(4)