PNUT Seminar: A Holographic View of the QCD Axion

 

 

Abstract: The QCD axion provides a solution to both the strong CP and dark matter problems in the Standard Model. However, the axion solution requires that gravitational violations of the Peccei-Quinn global symmetry be suppressed to extremely high order. This so-called axion quality problem can be addressed in 5D models with a holographic (AdS/CFT) interpretation that predict flavor-dependent axion-fermion couplings. Moreover, 5D models also allow for the intriguing possibility that the axion mass could be enhanced while still solving the strong CP problem. This holographic view offers a complete framework for studying the QCD axion, with implications for ongoing searches and early-universe cosmology.