Solar System motions and the cosmological constant: a new approach

TL;DR

This study tests the influence of the cosmological constant on planetary orbits using precise astronomical data, finding no evidence of such effects within current measurement limits, thus constraining alternative gravity models.

Contribution

It introduces a novel ratio-based method to compare planetary perihelion precessions for testing the cosmological constant's effects, improving upon previous individual planet analyses.

Findings

No detectable influence of the cosmological constant on planetary precessions.

Current data constraints are too weak to confirm the predicted effects.

Future spacecraft missions could tighten these constraints.

Abstract

We use the corrections to the Newton-Einstein secular precessions of the longitudes of perihelia of some planets (Mercury, Earth, Mars, Jupiter, Saturn) of the Solar System, phenomenologically estimated as solve-for parameters by the Russian astronomer E.V. Pitjeva in a global fit of almost one century of data with the EPM2004 ephemerides, in order to put on the test the expression for the perihelion precession induced by an uniform cosmological constant Lambda in the framework of the Schwarzschild-de Sitter (or Kottler) space-time. We compare such an extra-rate to the estimated corrections to the planetary perihelion precessions by taking their ratio for different pairs of planets instead of using one perihelion at a time for each planet separately, as done so far in literature. The answer is neatly negative, even by further re-scaling by a factor 10 (and even 100 for Saturn) the errors in the estimated extra-precessions of the perihelia released by Pitjeva. Our conclusions hold also for any other metric perturbation having the same dependence on the spatial coordinates, as those induced by other general relativistic cosmological scenarios and by many modified models of gravity. Currently ongoing and planned interplanetary spacecraft-based missions should improve our knowledge of the planets' orbits allowing for more stringent constraints.