Two Fluids in f(T) Gravity with Observational Constraints

A locally rotationally symmetric Bianchi type-I model has been studied with two fluids within the framework of the f(T) theory of gravity. Bianchi type-I is an immediate generalization of the Friedmann–Lemaître–Robertson–Walker (FLRW) metric. We have derived the exact field equations in f(T) gravity by considering the Bianchi type-I metric and applying the action for f(T) theory of gravity. We have utilized the torsion scalar T and the Lagrangian for matter. The field equations are obtained by taking the variation of the action with respect to the vierbein, leading to a set of equations that includes the energy–momentum tensor for two fluid sources: matter and radiation. We fit the H(z) curve using 57 data points and the R2-test, achieving an R2 value of 0.9321, indicating a strong fit with the Observational Hubble Dataset (OHD). Cosmological parameters like energy density, pressure, and state finder diagnostics are also discussed. © 2024 Elsevier B.V.