Exploring the Bianchi-IX universe within Brans–Dicke theory and a deceleration parameter

In this paper, we have presented the cosmological model in Brans–Dicke theory (BDT) of gravity for a Bianchi type-IX spacetime. We obtained the exact solutions of the field equations by applying the new form of deceleration parameter, i.e. fractional linear varying deceleration parameter (FLVDP) as proposed by R. K. Mishra and A. Chand [Astrophys. Space Sci. 361, 1 (2016)]. In this paper, we have also presented the physical and geometric properties and mathematical analysis of the proposed model. Then we have provided the energy conditions and statefinder diagnostic.