OKC Colloquium: Astrophysical searches for axions

Axions and axion-like particles are well motivated extensions to the Standard Model. If axions exist, they may be produced in abundance in a wide range of astrophysical systems. Such systems involve both distance scales and energy scales far larger than we could hope to reproduce on Earth, making them an excellent testbed for new physics. These extreme environments allow us to probe even very weak couplings between axions and the Standard Model with increasing reach, aided by continuing improvements in our observational capabilities. I will discuss current directions in astrophysical searches for axions, ranging from axion-photon interconversion to superradiant instabilities. I will suggest how these techniques will improve with the next generation of telescopes.