A flat FLRW dark energy model in f(Q,C)-gravity theory with observational constraints

Abstract

In the recently suggested modified non-metricity gravity theory with boundary terms in a flat FLRWspacetime universe, dark energy scenarios of cosmological models are examined in this study. An arbitrary function, $f(Q,C)=Q+\alpha C^2$, has been taken into consideration, where Q is the non-metricity scalar, C is the boundary term denoted by $C=R-Q$, and $\alpha$ is the model parameter, for the action that is quadratic in C. The Hubble function $H(z)=H0[c_1(1+z{)}^n+c_2{]}^{1/2}$, where H0 is the current value of the Hubble constant and n c, and $c_2$ are arbitrary parameters with $c_1+c_2=1$, has been used to examine the dark energy characteristics of the model. We discovered a transit phase expanding universe model that is both decelerated in the past and accelerated in the present, and we discovered that the dark energy equation of state (EoS) $({\omega }^{de})$ behaves as $(-1\le {\omega }^{de}<2)$. The $O_m$ diagnostic analysis reveals the quintessence behavior in the present and the cosmological constant scenario in the late-time universe. Finally, we calculated the universe's current age, which was found to be quite similar to recent data.

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