Non-Interacting New Agegraphic Dark Energy Model in $f(Q)$ Gravity
M. Sharif, Madiha Ajmal
TL;DR
This work investigates the reconstruction of a non-interacting new agegraphic dark energy (NADE) model within $f(Q)$ gravity in a spatially flat FRW universe. By adopting a power-law scale factor $a(t)=a_0 t^{m}$, it derives the modified Friedmann framework with NADE density given by $\varrho_D=\frac{3 n^2}{\zeta^{2}}$ where $\zeta=\int_{0}^{t}\frac{dt}{a}$, and reconstructs the corresponding $f(Q)$ function. The evolution is analyzed through the equation of state parameter $\omega_D$ and its derivative, the statefinder pair $(r,s)$, and stability is assessed via the squared sound speed $v_s^2$, highlighting quintessence-like behavior and Chaplygin-gas trajectories. The results indicate that the non-interacting NADE model in $f(Q)$ gravity provides a viable geometric route to late-time acceleration and can address the cosmic coincidence problem while remaining compatible with observational constraints.
Abstract
In this study, we explore the reconstruction of a new agegraphic dark energy model in a flat Friedmann-Robertson-Walker spacetime by $f(Q)$ gravity framework, where $Q$ represents non-metricity. We assume that the scale factor follows a power-law and explore how this model aligns with the expanding universe. In this perspective, we develop a new agegraphic $f(Q)$ model and analyze the graphical behavior for cosmic evolution. We analyze physical characteristics of the model using the equation of state parameter, $(ω_{D}-ω^{\prime}_{D})$ and the $(r-s)$ planes. The equation of state parameter indicates a quintessence era characterized by accelerated expansion. The $(ω_{D}-ω^{\prime}_{D})$-plane identifies the freezing region and the Chaplygin gas model is represented in the $(r-s)$-plane. Finally, we examine the stability of the non-interacting model by evaluating the squared speed of sound. Our findings show that the non-interacting new agegraphic dark energy model effectively resolves the cosmic coincidence problem.