Acceleration and stability of universe models in non-linear Weyl-type f ( Q , T ) gravity

In the present study, we investigate the cosmic acceleration and stability of the generalized Weyl-type Formula: see text gravity model in a flat Friedmann-Lemaître–Robertson–Walker (FLRW) spacetime manifold. We consider both linear Formula: see text and nonlinear Formula: see text functions with dimensionless constants Formula: see text, Formula: see text, and Formula: see text to investigate the model in both cases of the Lagrange multiplier Formula: see text as constant and dynamical. We solve the field equations for the Weyl vector field component Formula: see text, the Hubble function Formula: see text, and Formula: see text for the dust and dark fluid sources. We constrain the model parameters using the Monte Carlo Markov Chain (MCMC) technique in the joint analysis of the Cosmic Chronometer (CC) dataset of the Hubble function Formula: see text and the Pantheon+SH0ES sample of the SNe Ia dataset. We discuss the characteristics of the model with the cosmic evolution of the effective equation of state (EoS) parameter Formula: see text, deceleration parameter Formula: see text, Lagrange multiplier Formula: see text, effective dynamical mass Formula: see text of the Weyl vector particle, and transition redshift Formula: see text. We also investigate the models’ stability and physical acceptability. We find a transit phase accelerating a stable universe model with Formula: see text km/s/Mpc, Formula: see text, Formula: see text, transition redshift Formula: see text, and Formula: see text in which particle creation or annihilation may occur during the interaction of matter-geometry.