Cosmological Diagnostics and Stability of Dark Energy Model in Non-Metric Gravity

Abstract

In this study, we investigate the dynamics of generalized ghost pilgrim dark energy in the background of f(Q,C) gravity, where Q is the non-metricity scalar and C represents the boundary term. To complete this objective, we take an isotropic and homogeneous universe with an ideal matter distribution. Our analysis includes a scenario with non-interacting fluids, encompassing both dark matter and dark energy. To understand the cosmic dynamics, we reconstruct a f(Q,C) model and examine its influence on the universe evolution. We explore key cosmological factors, i.e., state variable, the behavior of (ωD - ω'D)-plane and the statefinder diagnostic pair, which help to analyze the cosmic expansion. A crucial aspect of our analysis is the stability of generalized ghost pilgrim dark energy model via the squared sound speed method, confirming its viability in supporting the observed accelerated expansion. Our findings are consistent with observational data, demonstrating that f(Q,C) gravity provides a robust theoretical foundation for describing dark energy and the universe large-scale dynamics. This work not only deep our understanding of modified gravity and mysterious energy but also offers new insights into alternative explanation for cosmic acceleration beyond standard paradigms.