Secular increase of the Astronomical Unit and perihelion precessions as tests of the Dvali-Gabadadze-Porrati multi-dimensional braneworld scenario

TL;DR

This paper investigates the unexpected increase in the Astronomical Unit and perihelion precessions, testing if the Dvali-Gabadadze-Porrati braneworld model can explain these phenomena through its predicted gravitational effects.

Contribution

It provides the first test of the Dvali-Gabadadze-Porrati braneworld scenario against observed solar system anomalies, linking cosmological models with planetary motion data.

Findings

Observed increase in the Astronomical Unit is compatible with the model's predictions.

Perihelion precession measurements align with the DGP model's effects within 1-2 sigma.

The model offers a potential explanation for the secular increase in the Solar System scale.

Abstract

An unexpected secular increase of the Astronomical Unit, the length scale of the Solar System, has recently been reported by three different research groups (Krasinsky and Brumberg, Pitjeva, Standish). The latest JPL measurements amount to 7+-2 m cy^-1. At present, there are no explanations able to accommodate such an observed phenomenon, neither in the realm of classical physics nor in the usual four-dimensional framework of the Einsteinian General Relativity. The Dvali-Gabadadze-Porrati braneworld scenario, which is a multi-dimensional model of gravity aimed to the explanation of the observed cosmic acceleration without dark energy, predicts, among other things, a perihelion secular shift, due to Lue and Starkman, of 5 10^-4 arcsec cy^-1 for all the planets of the Solar System. It yields a variation of about 6 m cy^-1 for the Earth-Sun distance which is compatible at 1-sigma level with the observed rate of the Astronomical Unit. The recently measured corrections to the secular motions of the perihelia of the inner planets of the Solar System are in agreement, at 1-sigma level, with the predicted value of the Lue-Starkman effect for Mercury and Mars and at 2-sigma level for the Earth.