Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-01-30
JETP Lett.77:201-206,2003; Pisma Zh.Eksp.Teor.Fiz.77:249-253,2003
Astronomy and Astrophysics
Astrophysics
7 pages, 3 figures. Final version to be published in JETP Lett., presentation shortened, references added and updated, conside
Scientific paper
10.1134/1.1574831
We introduce a new cosmological diagnostic pair $\lbrace r,s\rbrace$ called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters $H(z)$ and $q(z)$, is constructed from the scale factor of the Universe and its derivatives only. The parameter $r(z)$ forms the next step in the hierarchy of geometrical cosmological parameters used to study the Universe after $H$ and $q$, while the parameter $s(z)$ is a linear combination of $q$ and $r$ chosen in such a way that it does not depend upon the dark energy density $\Omega_X(z)$. The Statefinder pair $\lbrace r,s\rbrace$ is algebraically related to the the dark energy pressure-to-energy ratio $w=p/\epsilon$ 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 $w$, including a cosmological constant ($w = -1$). The Statefinder pair can be determined to very good accuracy from a SNAP type experiment.
Alam Ujjaini
Sahni Varun
Saini Tarun Deep
Starobinsky Alexei A.
No associations
LandOfFree
Statefinder -- a new geometrical diagnostic of dark energy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Statefinder -- a new geometrical diagnostic of dark energy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Statefinder -- a new geometrical diagnostic of dark energy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-583531