Probing the interaction between dark energy and dark matter with the parametrized post-Friedmann approach

• Published in: Science China. Physics, mechanics & astronomy mechanics & astronomy, 2017-05, Vol.60 (5), p.82-84, Article 050431
• Main Author: Zhang, Xin
• Format: Article
• Language: English
• Subjects: Astronomy; Classical and Continuum Physics; Dark energy; Dark matter; News & Views; Observations and Techniques; Physics; Physics and Astronomy; 参数化; 参考文献; 宇宙演化; 弗里德曼; 探测; 暗物质; 暗能量; 相互作用
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-017-9013-7

In the current universe, the dominant energy components are dark energy and dark matter. There is a longstanding conjecture that there might be some direct coupling between dark energy and dark matter （for a recent review, see ref. [1]）. The advantages for considering such a possibility include, for example, those that it can alleviate the ＂cosmic coincidence＂ puzzle, can avoid the ＂big rip＂ in a phantom scenario, and so on. We call the scenario in which dark energy directly in- teracts with dark matter the ＂interacting dark energy＂ （IDE） scenario. Actually, besides the above reasons of theoretical aspect, one should be more concerned with the observational issue： How can we detect this interaction （this is essentially a kind of ＂fifth force＂） or falsify this scenario by using the observations？ This requires us to be able to calculate how it affects the cosmological evolution, including both aspects of expansion history and growth of structure.