New Agegraphic Dark Energy Driven Reconstruction of \boldmath{$f(Q)$} Gravity and its Cosmological Implications

TL;DR

This paper reconstructs an alternative gravity model based on NADE to explain late-time cosmic acceleration, fitting observational data well and showing deviations from the standard b1CDM model.

Contribution

It introduces a novel reconstruction of f(Q) gravity inspired by NADE, demonstrating its viability with observational constraints and cosmological diagnostics.

Findings

Reconstructed f(Q) model aligns with BAO data and outperforms b1CDM.

Model exhibits transition from deceleration to acceleration at zrom 0.5209 to 0.8126.

Energy conditions are satisfied except SEC at low redshift, consistent with acceleration.

Abstract

In this work, we perform reconstruction of \( f(Q) \) gravity inspired by the New Agegraphic Dark Energy (NADE) model, aiming to account for the Universe's late time acceleration without invoking a cosmological constant. Utilizing a power law scale factor \( a(t) = a_0 t^h \), we derive an analytic form for \( f(Q) \) based on a correspondence with NADE, where the conformal time serves as the infrared cutoff. The resulting model naturally recovers General Relativity in the limit and exhibits a geometrically motivated dark energy component. We constrain the model parameters using recent Baryon Acoustic Oscillation (BAO) data from DESI DR2 BAO and previous BAO observations through the Markov Chain Monte Carlo (MCMC) analysis. The reconstructed Hubble parameter \( H(z) \) demonstrates excellent agreement with observational data, achieving high \( R^2 \) values and low \(\chi^2_{\min}\), AIC, and BIC scores, outperforming the standard \( \Lambda \)CDM model. Further, we investigate the cosmological evolution using the deceleration parameter \( q(z) \), effective equation of state \( \omega_{\mathrm{eff}}(z) \), and Om diagnostics. The model exhibits a clear transition from deceleration to acceleration with a present value \( q(0) \in \left[-0.5879, -0.3333\right] \) and transition redshift $z_{\mathrm{tr}} \sim 0.5209-0.8126$, while maintaining \( -1 < \omega_{\mathrm{eff}}(z) < -1/3 \), indicating quintessence like behavior. Om diagnostics consistently show a negative slope, further confirming deviation from \( \Lambda \)CDM. Energy condition analysis reveals that WEC, DEC, and NEC are satisfied, while SEC is violated only at low redshifts which is consistent with cosmic acceleration. Overall, the reconstructed \( f(Q) \) model provides a viable, observationally consistent, and theoretically motivated alternative to standard dark energy scenarios.