http://arxiv.org/abs/1611.07196
We use two model-independent methods to constrain the curvature of the universe. In the first method, we measure the curvature parameter ($\Omega_k^0$) by using the observations of the Hubble parameter and comoving distances obtained from the age of galaxies. Secondly, we also use an indirect method based on the mean image separation statistics of gravitationally lensed quasars. The basis of this methodology is that the average image separation of lensed images will show a positive, negative or no correlation with the source redshift in a closed, open or flat Universe respectively. In order to smoothen the datasets used in both the methods, we use a non-parametric method namely, Gaussian process (GP). However, the bound on the present value of $\Omega_k^0$ obtained from Method I (from age of galaxies) using GP technique is $\Omega_k^0= -0.22\pm0.58$. But the combined result from both the methods suggests that our universe is homogeneous and spatially flat within 3$\sigma$ level.
A. Rana, D. Jain, S. Mahajan, et. al.
Wed, 23 Nov 16
57/68
Comments: 14 pages, 8 figures and 2 tables
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