Mathematical and Physical Aspects of Topologically Protected States

Chiral anomaly, topological field theory and topological states of matter

Juerg Froehlich

ETH Zurich


I will discuss the roles played by the chiral anomaly and by topological field theory in understanding aspects of the theory of the fractional quantum Hall effect and of time-reversal invariant "topological insulators". In particular, I will discuss the "anomalous" boundary/edge degrees of freedom observed in these systems and describe ideas on the nature of their quasi-particles.