부산대학교 도서관

Summary: ``Since the discovery of the accelerated expansion of thepresent universe, significant theoretical developments have been madein the area of modified gravity. In the meantime, cosmologicalobservations have been providing more high-quality data, allowing us toexplore gravity on cosmological scales. To bridge the recenttheoretical developments and observations, we present an overview of avariety of modified theories of gravity and the cosmologicalobservables in the cosmic microwave background and large-scalestructure, supplemented with a summary of predictions for cosmologicalobservables derived from cosmological perturbations and sophisticatednumerical studies. We specifically consider scalar-tensor theories inthe Horndeski and DHOST family, massive gravity/bigravity,vector-tensor theories, metric-affine gravity, and cuscuton/minimallymodified gravity, and discuss the current status of those theories withemphasis on their physical motivations, validity, appealing features,the level of maturity, and calculability. We conclude that theHorndeski theory is one of the most well-developed theories of modifiedgravity, although several remaining issues are left for futureobservations. The paper aims to help to develop strategies for testinggravity with ongoing and forthcoming cosmological observations.''