The problems of dark energy and dark matter revealed by astronomical observations have posed a major challenge to fundamental physics. Motivated by this, together with the considerations of the quantization of gravity and the unification of fundamental interactions, various new theories of gravity alternative to general relativity have been proposed, in an attempt to solve the above problems by modifying the fundamental theories. The history of modified gravity theories is almost as long as the history of general relativity. In a broad sense, the candidate theories of gravity that differ from general relativity all fall under the category of modified gravity. The most popular modified gravity theories in cosmology are f(R) theory and Brans-Dicke theory as well as their extensions to the general scalar-tensor theories of gravity. The modified gravity theories that are closer to the idea of the gauge field theory are the Poincare gauge theories of gravity and Weyl gauge theory of gravity. Kaluza-Klein theory is one of the representatives of higher dimensional theories of gravity, aiming at unifying fundamental interactions.

Representative Works of the Center.

1. Hongguang Liu, Xin Wang, Haida Li, Yongge Ma, "Distinguishing f(R) theories from general relativity by gravitational lensing effect ", Eur. Phys. J. C 77 (2017), 723.

2. Peng Xu and Yongge Ma, “Five-dimensional PPN formalism and experimental test of Kaluza-Klein theory”, Phys. Lett. B656 (2007), 165.

3. Li-e Qiang, Yongge Ma, Muxin Han, and Dan Yu, "Five-dimensional Brans-Dicke theory and cosmic acceleration", Phys. Rev. D 71 (2005), 061501 (Rapid Communication).