Dark energy and neutrino mass constraints from weak lensing, supernova, and relative galaxy ages

Abstract

We use the current weak lensing data to constrain the equation of state of dark energy $w$ and the total mass of massive neutrinos $\sum m_{\hat{I}}½$. The constraint on $w$ would be weak if only the current weak lensing data are used. With the addition of other observational data such as the type Ia supernovae, baryon acoustic oscillation, and the high redshift Hubble parameter data $H(z)$ derived from relative galaxy ages to break the degeneracy, the result is significantly improved. For the pure $w$CDM model without massive neutrinos, we find $w=-1.00_{-0.12}^{+0.10}$. For the $w$CDM model with the massive neutrino component, we show that the constraint on $w$ is almost unchanged, there is very little degeneracy between $w$ and $\sum m_{\hat{I}}½$. After marginalizing over other parameters, we obtain the probability distribution function of $\sum m_{\hat{I}}½$, and find that the upper limit is $\sum m_{\hat{I}}½\le 0.8$ eV at 95.5% confidence level for the combined data sets. Our constraints of $w$ and $\sum m_{\hat{I}}½$ are both compatible and comparable with the constraints obtained from the WMAP 5-year data.

8 pages, 6 figures