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arXiv · 2412.19852

Parameterized Deceleration in $f(Q,C)$ Gravity: A Logarithmic Approach

S. R. Bhoyar·Yash B. Ingole
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Abstract

This study explores a distinctive logarithmic parameterization of the deceleration parameter within the $f(Q, C)$ gravity framework, incorporating a nonlinear functional form $f(Q, C) = \gamma_1 Q^n + \gamma_2 C$, where $Q$ and $C$ denote the nonmetricity scalar and boundary term, respectively, and $n \geq 1$. This approach provides a unique perspective on the universe's accelerated expansion without resorting to exotic fields. Using observational data from Hubble measurements (OHD) and the Pantheon+SH0ES Type Ia supernovae dataset, the model parameters were constrained through a $\chi^2$ minimization technique. The analysis reveals a transition from deceleration to acceleration in the expansion history of the universe, with the transition redshifts $z_t \approx 0.98$ (OHD) and $z_t \approx 0.76$ (Pantheon+SH0ES). The model demonstrates consistency with observations, offering insights into the dynamics of dark energy and alternative gravity theories, while effectively modeling cosmic evolution across epochs.

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S. R. Bhoyar, Yash B. Ingole. 2024-12-25. Parameterized Deceleration in $f(Q,C)$ Gravity: A Logarithmic Approach. https://doi.org/10.1016/j.newast.2025.102386

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