An effective formalism for testing extensions to General Relativity with gravitational waves

Understand

The recent direct observation of gravitational waves (GW) from merging black holes opens up the possibility of exploring the theory of gravity in the strong regime at an unprecedented level.

• It is therefore interesting to explore which extensions to General Relativity (GR) could be detected.
• We construct an Effective Field Theory (EFT) satisfying the following requirements.
• It is testable with GW observations; it is consistent with other experiments, including short distance tests of GR; it agrees with widely accepted principles of physics, such as locality, causality and unitarity; and it does not involve new light degrees of freedom.