A novel PBH production mechanism from non-Abelian gauge fields during inflation

Understand

We consider the case of axion-like particles (ALPs) during inflation.

• When coupled to a non-Abelian gauge sector via a Chern-Simons term, ALPs support an intriguing, testable, phenomenology with very distinctive features including chiral primordial gravitational waves.
• For sufficiently small values of the gauge vev and coupling, scalar perturbations in the gauge sector exhibit a known instability.
• We harness the power of such instability for primordial black hole (PBH) generation.