Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

TL;DR

This paper refines constraints on Kaluza-Klein gravity by analyzing Solar System experiments, especially the gravitational time delay, leading to significantly tighter bounds on the theory's parameters.

Contribution

It provides more stringent upper bounds on Kaluza-Klein gravity effects using Solar System observations, especially the Cassini data, improving previous constraints by up to two orders of magnitude.

Findings

KK gravity effects are highly constrained in the Solar System.

The fifth-dimensional space in the soliton case is very flat.

Constraints on KK gravity are significantly improved.

Abstract

As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of \textit{Cassini} to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun.