标题： 用双源平面强透镜约束暗能量状态方程 显示英文标题

标题： Constraining the dark energy equation of state with double source plane strong lenses

摘要： 我们研究通过测量强引力透镜系统中两个源平面的爱因斯坦半径比值来限制暗能量状态方程的可能性。 该量与哈勃参数无关，并直接测量角直径距离随红移的变化。 我们研究了单个双源平面系统的前景以及通过重新观测已从光度选择目录（如CASSOWARY）或光谱选择目录（如SLACS）中发现的单源透镜群体而获得的系统群体的前景。 我们发现，仅需少量双源平面系统即可获得与当前数据集（68%CL下暗能量状态方程15%的不确定性）相当的约束。 我们还发现，该方法在Omega_M和w之间的退化几乎与CMB和BAO测量的退化正交，使该方法与当前探测手段高度互补。 显示英文摘要

摘要： We investigate the possibility of constraining the dark energy equation of state by measuring the ratio of Einstein radii in a strong gravitational lens system with two source planes. This quantity is independent of the Hubble parameter and directly measures the growth of angular diameter distances as a function of redshift. We investigate the prospects for a single double source plane system and for a forecast population of systems discovered by re-observing a population of single source lenses already known from a photometrically selected catalogue such as CASSOWARY or from a spectroscopically selected catalogue such as SLACS. We find that constraints comparable to current data-sets (15% uncertainty on the dark equation of state at 68%CL) are possible with a handful of double source plane systems. We also find that the method's degeneracy between Omega_M and w is almost orthogonal to that of CMB and BAO measurements, making this method highly complimentary to current probes.