Past exam of the mathematics course of the University of Cambridge 2019 ii Paper 2 36D a Solution Created 2026-09-24 Updated 2026-10-03
This is the Schwarzschild-de Sitter spacetime. Its geodesic Lagrangian may be taken asTime-translation and rotational symmetry give three independent integrals of motion, which may be chosen asThe constant norm of the tangent is , where for a timelike geodesic parametrized by proper time and for a null geodesic. Substitution givesand hence