Cosmological Tests for a Linear Coasting Cosmology
  A strictly linear evolution of the scale factor is a characteristic feature in several classes of alternative gravity theories. In this article we investigate the overall viability of an open linear coasting cosmological model. We report that this model is consistent with gravitational lensing statistics (within $1\sigma$) and accomodates old high-redshift galaxies. We finally conclude that such a linear coasting, $\a(t) = t$, is not ruled out on basis of these observational tests. 
Abha Dev, Margarita Safonova, Deepak Jain and Daksh Lohiya (University   of Delhi, India)