Instanton Operators in Five-Dimensional Gauge Theories

Understand

We discuss instanton operators in five-dimensional gauge theories.

• These are defined as disorder operators which create a non-vanishing second Chern class on a four-sphere surrounding their insertion point.
• As such they may be thought of as higher-dimensional analogues of three-dimensional monopole (or `t Hooft) operators.
• We argue that they play an important role in the enhancement of the Lorentz symmetry for maximally supersymmetric Yang-Mills to SO(1,5) at strong coupling.