Constrained ΛCDM dark energy models in higher derivative f (R, Lm,)-gravity theory

In the present paper, we have investigated dark energy scenarios in higher derivative f(R, L-m) 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, L-m) = gamma R-2 + lambda L-m(n), where R is the Ricci-scalar, L-m is matter Lagrangian, gamma, lambda and n are non-vanishing parameters. We have obtained contour plots of model parameters for the best fit values of (H-0, q(0), j(0), s(0), gamma, lambda, n, Omega(m0)) with 1 - sigma and 2 - sigma 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 rho(eff), p(eff) and omega(eff). We have found the values of effective equation of state parameter omega(eff) approximate to -0.96 at present and tends to cosmological constant value at late-time. We have found that the dark energy density term rho(Lambda) similar to Lambda and it behaves just like time-dependent cosmological constant Lambda-term. We have found a constrained Lambda CDM transit phase expanding and currently accelerating dark energy model. Also, we have estimated the present age of the universe as t(0) = 14.28 Gyrs.