https://doi.org/10.1140/epjp/s13360-020-00982-9
Regular Article
Solar System tests in Brans–Dicke and Palatini 
-theories
1
Department of Physics, University of Torino, via Pietro Giuria 1, 10125, Turin, Italy
2
Department of Mathematics, University of Torino, via Carlo Alberto 10, 10123, Turin, Italy
3
Istituto Nazionale di Fisica Nucleare (INFN), Sez. di Torino, via P. Giuria 1, 10125, Turin, Italy
Received:
3
November
2020
Accepted:
7
December
2020
Published online:
16
December
2020
We compare Mercury’s precession test in standard general relativity, Brans–Dicke theories (BD), and Palatini -theories. We avoid post-Newtonian approximation and compute exact precession in these theories. We show that the well-known mathematical equivalence between Palatini -theories and a specific subset of BD theories does not extend to a really physical equivalence among theories since equivalent models still allow a different incompatible precession for Mercury depending on the solution one chooses. As a result one cannot use BD equivalence to rule out Palatini -theories. On the contrary, we directly discuss that Palatini -theories can (and specific models do) easily pass Solar System tests as Mercury’s precession.
© The Author(s) 2020
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