  We derive boundary terms appropriate for the general Lanczos-Lovelock action
on a null boundary, when Dirichlet boundary conditions are imposed. We believe
that these boundary terms have been derived for the first time in the
literature. In this derivation, we rely only on the structure of the boundary
variation of the action for Lanczos-Lovelock gravity. We also provide the null
boundary term for Gauss-Bonnet gravity separately.

General Relativity and Quantum Cosmology