Just after the birth of Einstein’s general relativity (GR), attempts to generalize the theory started. Currently, a more general extension is to replace the Ricci curvature scalar in the Einstein-Hilbert action with some analytic function f(R). Focusing on a power class of generalization of GR, in which the Lagrangian is proportional to R1+δ (GR is reduced in the limit of δ→0), some authors found the best upper limit on δ by the precession of perihelion of Mercury with assuming that Mercuy follows a timelike geodesic.
   On the other hand, there exist three modern high-precision ephemerides so far: DE (JPL, USA), INPOP (IMCCE, France) and EPM (IAA RAS, Russia). These ephemerides are basically numerical integration of the equations of motion of the main planets of our solar system. Thanks to tracking data of spacecrafts orbiting or flying by the planets (e.g. radar/laser ranging, doppler tracking), these planetary ephemerides reach a great accuracy. Besides, these ephemerides provide the supplementary advances of the perihelia of the planets in the solar system. 
   Inspired by the above idea, this research tries to find new upper limits on the power of GR by making use of the supplementary advances of the perihelia provided by INPOP10a (IMCCE, France) and EPM2011 (IAA RAS, Russia) ephemerides. These two ephemerides were recently used in detecting gravitational effects and testing gravitational theories. Since INPOP10a and EPM2011are significantly improved compared with their previous versions, the research obtaines tighter limits on δ (see the table). 

By with DENG Xuemei 

   This work is done by Dr. Xue-Mei Deng of Purple Mountain Observatory who is collaborated with Dr. Yi Xie of Department of Astronomy in Nanjing University. And this research is supported by the National Nature Science Foundation of China and the National basic research program of China (Nos. 11473072, 1103085 and 11103010) and the Fundamental Research Program of Jiangsu Province of China (Nos. BK20131461 and BK2011553).  For more details, please see the following link: http://www.sciencedirect.com/science/article/pii/S1384107614001377