Earth-Moon Lagrangian points as a testbed for general relativity and effective field theories of gravity

TL;DR

This paper investigates how general relativity and effective field theories of gravity affect the positions of Earth-Moon Lagrangian points, finding millimeter-scale corrections that could inform future high-precision tests of gravity.

Contribution

It provides a detailed analysis of quantum and relativistic corrections to Lagrangian points in the Earth-Moon system, combining classical, relativistic, and effective field theory approaches.

Findings

Quantum corrections at L4 and L5 are about two millimeters.

Relativistic corrections to collinear points are below a millimeter.

Stable points show larger corrections than unstable points.

Abstract

In the restricted four-body problem consisting of the Earth, the Moon and the Sun as the primaries and a spacecraft as the planetoid, we take into account the solar perturbation in the description of the motion of a spacecraft in the vicinity of the stable Earth-Moon libration points L4 and L5 both in the classical regime and in the context of effective field theories of gravity. We then evaluate the location of all Lagrangian points in the Earth-Moon system within the framework of general relativity. For the points L4 and L5, the corrections of coordinates are of order a few millimeters. After that, we set up a scheme where the theory which is quantum corrected has as its classical counterpart the Einstein theory, instead of the Newtonian one. By virtue of the effective-gravity correction to the longdistance form of the potential among two point masses, all terms involving the ratio between the gravitational radius of the primary and its separation from the planetoid get modified. Within this framework, for the Lagrangian points of stable equilibrium, we find quantum corrections of order two millimeters, whereas for Lagrangian points of unstable equilibrium we find quantum corrections below a millimeter. Finally, general relativity corrections to Newtonian position of collinear Lagrangian points turn out to be below the millimiter, whereas on stable equilibrium points they are of order of a few millimiters.