EarthMoon Lagrangian points as a testbed for general relativity and effective field theories of gravity
Battista, Emmanuele and Dell' Agnello, Simone and Esposito, Giampiero and Di Fiore, Luciano and Simo, Jules and Grado, Aniello (2015) EarthMoon Lagrangian points as a testbed for general relativity and effective field theories of gravity. Physical Review D: Particles, Fields, Gravitation and Cosmology, 92. ISSN 15502368

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Abstract
We first analyse the restricted fourbody problem consisting of the Earth, the Moon and the Sun as the primaries and a spacecraft as the planetoid. This scheme allows us to take into account the solar perturbation in the description of the motion of a spacecraft in the vicinity of the stable EarthMoon libration points L4 and L5 both in the classical regime and in the context of effective field theories of gravity. A vehicle initially placed at L4 or L5 will not remain near the respective points. In particular, in the classical case the vehicle moves on a trajectory about the libration points for at least 700 days before escaping away. We show that this is true also if the modified longdistance Newtonian potential of effective gravity is employed. We also evaluate the impulse required to cancel out the perturbing force due to the Sun in order to force the spacecraft to stay precisely at L4 or L5. It turns out that this value is slightly modified with respect to the corresponding Newtonian one. In the second part of the paper, we first evaluate the location of all Lagrangian points in the EarthMoon system within the framework of general relativity. For the points L4 and L5, the corrections of coordinates are of order a few millimeters and describe a tiny departure from the equilateral triangle. 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. In other words, we deal with a theory involving quantum corrections to Einstein gravity, rather than to Newtonian gravity. By virtue of the effectivegravity correction to the long distance 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. In the latter case, for the point L1, general relativity corrects Newtonian theory by 7.61 meters, comparable, as an order of magnitude, with the lunar geodesic precession of about 3 meters per orbit. The latter is a cumulative effect accurately measured at the centimeter level through the lunar laser ranging positioning technique. Thus, it is possible to study a new laser ranging test of general relativity to measure the 7.61meter correction to the L1 Lagrangian point, an observable never used before in the SunEarthMoon system. Performing such an experiment requires controlling the propulsion to precisely reach L1, an instrumental accuracy comparable to the measurement of the lunar geodesic precession, understanding systematic effects resulting from thermal radiation and multibody gravitational perturbations. This will then be the basis to consider a secondgeneration experiment to study deviations of effective field theories of gravity from general relativity in the SunEarthMoon system.
Item type:  Article 

ID code:  54287 
Notes:  Date of Acceptance: 08/09/2015 
Keywords:  EarthMoon system, Lagrangian points, general relativity, field theory, gravity, four body problem, Mechanical engineering and machinery, Motor vehicles. Aeronautics. Astronautics, Mechanical Engineering, Aerospace Engineering, Control and Systems Engineering, Space and Planetary Science 
Subjects:  Technology > Mechanical engineering and machinery Technology > Motor vehicles. Aeronautics. Astronautics 
Department:  Faculty of Engineering > Mechanical and Aerospace Engineering 
Depositing user:  Pure Administrator 
Date deposited:  15 Sep 2015 09:16 
Last modified:  31 Mar 2019 06:57 
Related URLs:  
URI:  https://strathprints.strath.ac.uk/id/eprint/54287 
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