English

Reconstructions of Einstein-Aether Gravity from Barrow Agegraphic and New Barrow Agegraphic Dark Energy models: Examinations and Observational Limits

General Relativity and Quantum Cosmology 2025-06-13 v2 Cosmology and Nongalactic Astrophysics

Abstract

We present a comprehensive investigation exploring the theoretical framework of Einstein-Aether gravity theory when combined with two modified cosmological paradigms: the Barrow Agegraphic Dark Energy (BADE) and its newer variant, the New Barrow Agegraphic Dark Energy (NBADE). Our study focuses on reconstructing the functional form of the Einstein-Aether Lagrangian component F(K)F(K) from these phenomenological dark energy models. Model parameters are constrained using a Markov Chain Monte Carlo (MCMC) approach based on multiple datasets, including cosmic chronometers (CC), Baryon Acoustic Oscillations (BAO), and the Pantheon+SH0ES compilation. Using best-fit parameters, we analyze various cosmological diagnostics: Hubble and deceleration parameter evolution, dark energy equation of state ωDE\omega_{DE}, density parameter trajectories, ωDE\omega'_{DE}--ωDE\omega_{DE} phase space behavior, statefinder diagnostics (r,s)(r,s^*) and (r,q)(r,q), and Om(z) trajectories. Both models exhibit late-time acceleration, with the dark energy sector showing a quintessence-like nature in the current epoch and evolving toward a phantom regime in the future. Stability analysis based on the squared sound speed vs2v_s^2 highlights partial epoch-dependent stability. While our results demonstrate reasonable agreement with observational data and reveal physically plausible dynamics, the models do not yet offer a fundamentally superior alternative to other dark energy reconstructions. Nonetheless, their behavior under modified entropy assumptions and their flexibility in dynamical diagnostics provide a useful framework for probing non-standard extensions of Einstein-Aether gravity and dark energy phenomenology.

Keywords

Cite

@article{arxiv.2410.19897,
  title  = {Reconstructions of Einstein-Aether Gravity from Barrow Agegraphic and New Barrow Agegraphic Dark Energy models: Examinations and Observational Limits},
  author = {Banadipa Chakraborty and Tamal Mukhopadhyay and Anamika Kotal and Ujjal Debnath},
  journal= {arXiv preprint arXiv:2410.19897},
  year   = {2025}
}

Comments

33 pages, 33 figures. All comments are welcome