Accelerating cosmological models in Hoyle–Narlikar gravity with observational constraints.

In this paper, we explore the cosmic acceleration and the physical aspects of the dark energy nature in Hoyle–Narlikar's creation-field theory, taking into account observational constraints. We find analytical solutions to the modified field equations for a specific choice of creation field C (t) = t + ∫ k a n + c 1 with certain background fluid sources as a barotropic fluid and a radiation fluid in a flat Friedmann–Lemaître–Robertson–Walker (FLRW) spacetime universe. From there, we use observational constraints with data from the cosmic chronometer (CC) Hubble data and the apparent magnitude from the Pantheon SNe sample to get the model parameters' constrained values with σ 1 and σ 2 confidence levels. We look at the physical properties of the models we've made using these estimated values of model parameters. To do this, we look at the deceleration parameter q (z) , the effective equation of state parameter ω eff , the jerk parameter j (z) , the snap parameter s (z) , and the energy conditions. We also examine the cosmic behavior of square sound speed c s 2 for the test of causality and viability of the models. We measure the present age of the universe and transition redshift z t for the signature-flipping point. We obtain two transit-phase accelerating universe models with H 0 = 6 7. 0 ± 3. 2 , 6 9. 6 ± 3. 2 Km/s/Mpc, q 0 = − 0. 4 5 8 6 , − 0. 5 9 1 7 , z t = 0. 6 3 8 3 , 0. 6 7 5 1 , and ω eff 0 = − 0. 6 3 9 1 , − 0. 7 2 7 8 , respectively, with barotropic and radiation fluid sources. [ABSTRACT FROM AUTHOR]