ON LIE SYMMETRIES OF CERTAIN SPHERICALLY SYMMETRIC SYSTEMS IN GENERAL RELATIVITY

摘要

We discuss certain aspects of Lie-point symmetries in spherically symmetric systems of gravitational physics. Lie symmetries are helpful in solving differential equations. General concepts and a few examples are given: perfect fluid in shearfree motion, the conformal Weyl theory and a higher derivative gravity which is equivalent to General Relativity coupled to certain nonlinear spin-2 field theory.