Fundamental Physics with the Laser Astrometric Test Of Relativity

LATOR Collaboration; S. G. Turyshev; H. Dittus; M. Shao; K. L. Nordtvedt, Jr.; C. Laemmerzahl; S. Theil; W. Ertmer; E. Rasel; R. Foerstner; U. Johann; S. Klioner; M. Soffel; B. Dachwald; W. Seboldt; V. Perlick; M. C. W. Sandford; R. Bingham; B. Kent; T. J. Sumner; O. Bertolami; J. Paramos; B. Christophe; B. Foulon; P. Touboul; P. Bouyer; T. Damour; S. Reynaud; C. Salomon; A. Brillet; F. Bondu; J. -F. Mangin; E. Samain; C. Erd; J. C. Grenouilleau; D. Izzo; A. Rathke; S. W. Asmar; M. Colavita; Y. Gursel

arXiv · gr-qc/0506104

Fundamental Physics with the Laser Astrometric Test Of Relativity

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Abstract

The Laser Astrometric Test Of Relativity (LATOR) is a joint European-U.S. Michelson-Morley-type experiment designed to test the pure tensor metric nature of gravitation - a fundamental postulate of Einstein's theory of general relativity. By using a combination of independent time-series of highly accurate gravitational deflection of light in the immediate proximity to the Sun, along with measurements of the Shapiro time delay on interplanetary scales (to a precision respectively better than 0.1 picoradians and 1 cm), LATOR will significantly improve our knowledge of relativistic gravity. The primary mission objective is to i) measure the key post-Newtonian Eddington parameter γwith accuracy of a part in 10^9. (1-γ) is a direct measure for presence of a new interaction in gravitational theory, and, in its search, LATOR goes a factor 30,000 beyond the present best result, Cassini's 2003 test. The mission will also provide: ii) first measurement of gravity's non-linear effects on light to ~0.01% accuracy; including both the Eddington βparameter and also the spatial metric's 2nd order potential contribution (never measured before); iii) direct measurement of the solar quadrupole moment J2 (currently unavailable) to accuracy of a part in 200 of its expected size; iv) direct measurement of the "frame-dragging" effect on light by the Sun's gravitomagnetic field, to 1% accuracy. LATOR's primary measurement pushes to unprecedented accuracy the search for cosmologically relevant scalar-tensor theories of gravity by looking for a remnant scalar field in today's solar system. We discuss the mission design of this proposed experiment.

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LATOR Collaboration, S. G. Turyshev, H. Dittus, M. Shao, K. L. Nordtvedt, Jr., C. Laemmerzahl, S. Theil, W. Ertmer, E. Rasel, R. Foerstner, U. Johann, S. Klioner, M. Soffel, B. Dachwald, W. Seboldt, V. Perlick, M. C. W. Sandford, R. Bingham, B. Kent, T. J. Sumner, O. Bertolami, J. Paramos, B. Christophe, B. Foulon, P. Touboul, P. Bouyer, T. Damour, S. Reynaud, C. Salomon, A. Brillet, F. Bondu, J. -F. Mangin, E. Samain, C. Erd, J. C. Grenouilleau, D. Izzo, A. Rathke, S. W. Asmar, M. Colavita, Y. Gursel. 2005-07-22. Fundamental Physics with the Laser Astrometric Test Of Relativity. https://arxiv.org/abs/gr-qc/0506104

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