Talk abstract details

We present the package Invar, a fast manipulator of scalars of a metric-compatible Riemann tensor. Invar uses highly efficient algorithms of permutation group theory to handle the permutation symmetries of the Riemann tensor, and a database with all relations given by the cyclic and dimension-dependent identities up to polynomic degree 7. That allows us to manipulate arbitrary degree 7 polynomials of Riemann scalars (and their duals) within seconds. In particular, the old problem of expressing Riemann scalars in terms of a complete basis is solved.