Weak gravity at micron scales from dark bubble cosmology and its cosmological consequences

TL;DR

This paper explores a dark bubble cosmology model predicting weaker gravity at micron scales, with implications for experimental tests, early universe inflation, and the universe's matter content, offering novel insights into cosmological constant problems.

Contribution

It introduces a dark bubble model that predicts weaker gravity at small scales and explains early inflation and matter content without new fields, connecting quantum origins with observable phenomena.

Findings

Gravity weakens at micron scales, measurable via tabletop experiments.

The model predicts a period of early inflation driven by reduced gravity at high densities.

It provides a cosmological explanation for the matter content and the cosmological constant's timing.

Abstract

The dark bubble model makes a positive cosmological constant natural in string theory, and predicts several new physical phenomena within reach in the near future. In this paper we study the experimental consequences of the model for the strength of gravity at scales of order $10^{-5}$m. Contrary to other models of gravity involving extra dimensions, the dark bubble model predicts gravity to become weaker rather than stronger at small scales, compared to Newtonian gravity. In particular, we provide explicit predictions of measurable deviations using table top experiments. We also show how the same effect reduces the effective force of gravity at high energy densities in cosmology, leading to a period of early inflation without the need for anything beyond radiation. We also discuss the quantum origin of the universe with a 5D black hole acting as a catalyst for the nucleation of the dark bubble and how it accounts for the present matter content in the universe. This leads to a prediction of $\Omega_c \approx 5\times 10^{-4}$ for a positive curvature of the universe, suggesting an explanation of the why-now-problem of the cosmological constant. We end by speculating on how to incorporate AdS black shells as black hole mimickers within the dark bubble model.