https://doi.org/10.1051/epjconf/202637001018
Scalar field dark energy models with a dynamical equation of state for matter
1 Institute of Engineering & Management, School of University of Engineering and Management, Kolkata - 700091, India
2 Meghnad Saha Institute of Technology, Nazirabad, Kolkata - 700150, India
3 St. Paul’s C. M. College, 33/1 Raja Rammohan Sarani, Kolkata - 700009, India
* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.
Published online: 29 May 2026
Abstract
The red-shift zeq, which signifies the termination of the radiation-dominated epoch and the onset of the matter-dominated era, can serve as an important diagnostic tool in reconstructing dark-energy models. In this work, we introduce a variable equation of state for matter that enables a smooth and continuous transition from radiation domination to matter domination within a single framework. This formulation allows estimation of zeq in dark energy models and thereby facilitates assessment of their viability. To illustrate this approach, two one-parameter models involving minimally coupled scalar fields as dark energy are examined. We find that, although these models successfully reproduce the desired late-time cosmic behavior, the estimated value of zeq exhibits strong sensitivity to the parameter value in each case.
© The Authors, published by EDP Sciences, 2026
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
