Аннотации:
A flat Friedmann–Lematre–Robertson–Walker
(FLRW) spacetime metric was used to investigate some exact
cosmological models in metric-affine F(R, T ) gravity in
this paper. The considered modified Lagrangian function is
F(R, T ) = R + λT , where R is the Ricci curvature scalar,
T is the torsion scalar for the non-special connection, and λ
is a model parameter. We also wrote R = R(LC) + u and
T = T (W) + v, where R(LC) is the Ricci scalar curvature
with respect to the Levi–Civita connection and T (W) is the
torsion scalar with respect to the Weitzenbock connection,
and u and v are the functions of scale factor a(t), connection and its derivatives. For the scale factor a(t), we have
obtained two exact solutions of modified field equations in
two different situations of u and v. Using this scale factor,
we have obtained various geometrical parameters to investigate the universe’s cosmological properties. We used Markov
chain Monte Carlo (MCMC) simulation to analyze two types
of latest datasets: cosmic chronometer (CC) data (Hubble
data) points and Pantheon SNe Ia samples, and found the
model parameters that fit the observations best at 1 − σ, and
2 − σ regions. We have performed a comparative and relativistic study of geometrical and cosmological parameters.
In model-I, we have found that the effective equation of state
(EoS) parameter ωef f varies in the range −1 ≤ ωef f ≤ 0,
while in model-II, it varies as −1.0345 ≤ ωef f ≤ 0. We
found that both models are transit phase (moving from slowing down to speeding up) universes with a transition redshift
zt = 0.5874+0.2130 −0.0197 and zt = 0.6865+0.1719 −0.0303.
