Black Hole simulations in axi-dilaton gravity

Effective field theories of gravity featuring a scalar field coupled to quadratic curvature invariants are known to predict black holes with scalar hair. The phenomenology of hairy black holes has been studied extensively in the past, focusing either on Einstein-scalar-Gauss-Bonnet or dynamical Chern-Simons gravity. Both these models can be regarded as special cases of axi-dilaton gravity, i.e. an effective field theory that can be derived as a low-energy limit of string theory in four dimensions.

In this talk we will present results from our numerical simulations of axi-dilaton hair around isolated and binary black holes.