“From Theory to Experiment and Back”
Axions exist at an exciting intersection between theory and experiment where theory both guides and is guided by experiment. Axion strings contain information about charge quantization in the form of ’t Hooft anomalies. Trying to measure charge quantization using axion strings leads directly to a novel approach of analyzing CMB data. At the same time, experiments such as CASPER probing tuned axions have motivated the study of non-linear realizations of discrete symmetries. These non-linear realizations obey scaling relationships very different from those normally expected in “natural” theories and provide an interesting playground in which to better understand the electroweak hierarchy problem.