Observing axion potentials through gravitational waves

<!--HTML-->I will discuss the the production of gravitational waves which are sourced by the tensor perturbation of SU(2) gauge fields coupled to a spectator axion field. Even though string theory constructions provide a variety of potentials, they can be categorized based on the number of non-stationary inflection points. I will present the resulting GW templates arising from each potential type. I will focus on the case of a modulated (axion monodromy) potential and show how future observations of CMB B-modes can probe the oscillatory behavior of an axion potential, thus shedding light into the underlying string theory construction.