AN O(3) GLOBAL ANOMALY IN 0+1 DIMENSION
AN O(3) GLOBAL ANOMALY IN 0+1 DIMENSION
We present a simple exactly solvable quantum mechanical example of the global anomaly in an O(3) model with an odd number of fermionic triplets coupled to a gauge field on a circle. Because the fundamental group is non-trivial, π 1 (O(3))=Z 2 , fermionic level crossing—circling occurs in the eigenvalue …