Speaker
Description
In general relativity, the invariant classification of spacetimes is typically formulated in terms of a pseudo-algorithm proposed by Anders Karlhede in 1980. At first glance, this algorithm and its subsequent refinements do not bear much resemblence to Cartan's method for the equivalence of G-structures. Indeed, even if one limits the scope of the equivalence method to that of Riemannian geometries, it is difficult to perceive the relation between the two approaches. To wit, Karlhede's algorithm does not make use of the bundle of orthogonal frames and relies instead on iterated normalizations of the curvature tensor. My aim will be to explain the relativity approach to an audience familiar with the Cartan formalism and to highlight some computational advantages of this way of doing equivalence problems.
