GRJunction is a GRTensorII package for perfoming junction and thin-shell calculations in general relativity.

GRJunction allows users to specify a surface in a spacetime and determine quantities such as:
  • The first and second fundamental forms
  • Hamiltonian and ADM constraints
  • Two surfaces can be joined and then the user may calculate a variety of quantities including:
    • Darmois-Israel junction conditions (timelike/spacelike surfaces)
    • Barrabès-Israel formalism (null surfaces)
    • Stress-energy of the surface layer
    • Conservation and evolution laws for the surface

GRJunction is currently at our old site here.