Impact of Interacting Parameters on Dark Matter in an Interacting Dark Energy Model

Abstract This paper investigates a dark energy model within the Friedmann–Lemaître–Robertson–Walker cosmological framework, considering both interacting and noninteracting scenarios. Introducing an interaction scheme between dark energy and dark matter through a specific ansatz for the dark energy density ( ρ de ), we derive the Hubble parameter H ( z ) for both cases. To examine the influence of the interaction parameter on dark matter, we use a combination of observational data sets, including cosmic chronometers, Type Ia supernovae, and baryon acoustic oscillation measurements from the Dark Energy Spectroscopic Instrument Year 1 and Sloan Digital Sky Survey IV. We estimate the posterior distribution of each model parameter using the Markov Chain Monte Carlo method. In our analysis, we treat r d as a free parameter, allowing late-time data sets to constrain each model’s parameters, including H 0 , r d , and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi class="MJX-tex-calligraphic" mathvariant="script">M</mml:mi> </mml:math> . Our analysis shows that the interaction parameter affects dark matter. Additionally, we plot H ( z ), μ ( z ), Δ H ( z ), and Δ μ ( z ) with cosmographic parameters to examine the behavior of the late-time expansion of the Universe. Further, the Om ( z ) diagnostic is applied to distinguish interacting and noninteracting scenarios from the standard ΛCDM model. Finally, statistical metrics are used to compare different models, evaluate their goodness of fit, and determine the best-fit scenario.