Supersymmetric Chern-Simons Theory in Presence of a Boundary in the Light-Like Direction

Abstract: In this paper, we will analyze a three dimensional supersymmetric Chern-Simons theory on a manifold with a boundary. The boundary we will consider in this paper will be defined by $n\cdot x=0$, where $n$ is a light-like vector. It will be demonstrated that this boundary is preserved under the action of the $SIM(1)$ subgroup of the Lorentz group. Furthermore, the presence of this boundary will break half of the supersymmetry of the original theory. As the original Chern-Simons theory had $\mathcal{N} =1$ supersymmetry in absence of a boundary, it will only have $\mathcal{N}=1/2$ supersymmetry in presence of this boundary. We will also observe that the Chern-Simons theory can be made gauge invariant by introducing new degrees of freedom on the boundary. The gauge transformation of these new degrees of freedom will exactly cancel the boundary term obtained from the gauge transformation of the Chern-Simons theory.