Multiple Self-Dual Strings on M5-Branes

Understand

We show how to define Chern-Simons matter theories with boundary.

• Rather than imposing boundary conditions, we introduce new boundary degrees of freedom from the beginning and show how they can be used to cancel the gauge non-invariance of the Chern-Simons action.
• We apply this method to the ABJM theory with boundary.
• By imposing also boundary conformal invariance, we determine the required boundary action.