$\Lambda$CDM and Power-Law Expansion in Lyra's Geometry

Abstract

We establish in a cosmological model based on Lyra's geometry a relationship between a displacement vector field $ \phi_{\mu} $, the Hubble parameter and the matter energy density $ \rho_{m} $ (with a constant equation of state $0 \le \omega_{m} < 1$) via an arbitrary function $\alpha(t)$. For a pressureless matter ($ \omega_{m}=0 $) the effective equation of state $ \omega_{eff} $ is completely determined by $ \alpha(t) $. We subsequently investigate and find exact solutions in models yielding the $ \Lambda $CDM and a power-law expansion.