A possible role for the merger of clusters/voids in the cosmological expansion

TL;DR

This paper explores how the merger of cosmic clusters and voids, modeled as a variable dark energy fluid with a quadratic equation of state, can help resolve the Hubble tension and better explain the universe's accelerated expansion.

Contribution

It introduces a modified energy density model for cosmic fluids based on mergers, fitting observational data to demonstrate improved compatibility over standard models.

Findings

Merger processes can balance the cosmic expansion rate.

The model fits observational Hubble data better than $w$CDM.

The approach offers a potential solution to the Hubble tension.

Abstract

In this study, we use the merger process of clusters/voids in the role of variable dark energy fluid to alleviate the Hubble tension, which can lead to a balance in the cosmological expansion rate. To reach this target, we will introduce a modified form of energy density for cosmic fluid with the quadratic equation of state, and then we obtain Hubble, deceleration parameters, and luminosity distance for this fluid. To obtain the merger factor and other parameters of our model, we utilize the NONLINEARMODELFIT function within MATHEMATICA. By consideration of the local and global measurements of $\rm H_0$, and the equation of state parameter $w$ as the priory values and fitting our model with Observational Hubble Data (OHD) measurements, we will show that the merger of clusters/voids plays the role of balancing the cosmic expansion rate. Also, it will be shown that the model is more compatible than $w$CDM with the standard model to describe the accelerating universe.