Cancellation of Global Anomalies in Spontaneously Broken Gauge Theories
  We discuss the generalization to global gauge anomalies of the familiar procedure for the cancellation of local gauge anomalies in effective theories of spontaneously broken symmetries. We illustrate this mechanism in a recently proposed six-dimensional extension of the standard model. 
M. Fabbrichesi, R. Percacci, M. Piai and M. Serone