In this talk I will discuss the local existence of the characteristic initial value problem for the Einstein-Dirac system, which governs the interaction between gravity and spin-1/2 fields. To achieve this, we introduce the symmetric spinorial derivative of the Dirac field as the independent variables and derivative a “Weyl-curvature-free” equation system for them to close the bootstrap. Based on the existence results, we show that the focusing of the gravitational wave and the Weyl spinor flux leads to the formation of a trapped surface.
