Metric theories of gravity have been found [1] to include actions that may be free of ghosts and singularities. Such nonlocal actions, featuring an infinite number of derivative operators a’la string field theory, exhibit improved ultraviolet properties while recovering General Relativity in the infrared. This has important implications to cosmology and might pave the way for renormalizable, potentially asymptotically free theory of gravity.

[1] Phys.Rev.Lett. 108 (2012) 031101