# Alternate Theories of Gravity

A theory of gravitation that deviates slightly from Einstein’s General Theory of Relativity (GR). While we know that GR breaks down at small scales due to incompatibilities with quantum mechanics, large-scale astronomical tests of GR have consistently held. There are many different formulations for alternate theories of gravity that expand upon GR in some way. Pulsar timing is sensitive to a number of different of these tests.