Cosmological Constant Problem and $H_0$ Tension in Void-dominated Cosmology

TL;DR

This paper explores the cosmological constant problem and Hubble tension within a void-dominated cosmology, proposing that cosmic voids as interconnected bubbles can account for observed discrepancies across scales.

Contribution

It introduces a model where cosmic voids are treated as interconnected bubbles, providing a scale-dependent explanation for the cosmological constant and Hubble tension.

Findings

Cosmological constant varies from scale to scale by about 10^22.

Surface tension differences in cosmic bubbles may explain H_0 tension.

Void-based model aligns local and global measurements of H_0.

Abstract

In this work, we study the cosmological constant problem and Hubble tension in the void-dominated cosmology scenario \cite{Yusofi:2022hgg}. For this goal, we will first consider the cosmic voids in the cosmic web as interconnected ideal spherical bubbles at the early Planck scale and late large scale. By heuristic calculations for each cosmic void, we obtain particular mass density and cosmological constant that are the same order of magnitude as the entire universe on any scale. The values obtained for the cosmological constant vary from scale to scale. As a result, it will be shown that there is a roughly $\sim 10^{22}$ difference between the cosmological constant at the present and Planck scales. Finally, it will be shown that the slight difference between the surface tension of the cosmic bubbles may explain the tension between local and global measurements of $H_{\rm 0}$.