Constrained [formula omitted]CDM dark energy models in higher derivative [formula omitted]-gravity theory

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In the present paper, we have investigated dark energy scenarios in higher derivative f(R,Lm) gravity theory in a flat spacetime universe by constraining cosmographic series of Hubble function with Hubble constant H(z) datasets. We have considered an arbitrary function f(R,Lm)=γR2+λLmn, where R is the Ricci-scalar, Lm is matter Lagrangian, γ, λ and n are non-vanishing parameters. We have obtained contour plots of model parameters for the best fit values of (H0,q0,j0,s0,γ,λ,n,Ωm0) with 1−σ and 2−σ errors with H(z) datasets, and using these best fit model parameters, we have tried to explore the effective dark energy properties of the universe by defining the terms ρeff, peff and ωeff. We have found the values of effective equation of state parameter ωeff≈−0.96 at present and tends to cosmological constant value at late-time. We have found that the dark energy density term ρΛ∼Λ and it behaves just like time-dependent cosmological constant Λ-term. We have found a constrained ΛCDM transit phase expanding and currently accelerating dark energy model. Also, we have estimated the present age of the universe as t0=14.28 Gyrs.