Computational Algorithm for Covariant Series Expansions in General Relativity

We present a new algorithm for computing covariant power expansions of tensor fields in generalized Riemannian normal coordinates, introduced in some neighborhood of a parallelized k-dimensional submanifold (k = 0, 1, . . .< n; the case k = 0 corresponds to a point), by transforming the expansion...

Full description

Bibliographic Details
Main Authors: Potashov Ivan, Tsirulev Alexander
Format: Article
Language:English
Published: EDP Sciences 2018-01-01
Series:EPJ Web of Conferences
Online Access:https://doi.org/10.1051/epjconf/201817303021
Description
Summary:We present a new algorithm for computing covariant power expansions of tensor fields in generalized Riemannian normal coordinates, introduced in some neighborhood of a parallelized k-dimensional submanifold (k = 0, 1, . . .< n; the case k = 0 corresponds to a point), by transforming the expansions to the corresponding Taylor series. For an arbitrary real analytic tensor field, the coefficients of such series are expressed in terms of its covariant derivatives and covariant derivatives of the curvature and the torsion. The algorithm computes the corresponding Taylor polynomials of arbitrary orders for the field components and is applicable to connections that are, in general, nonmetric and not torsion-free. We show that this computational problem belongs to the complexity class LEXP.
ISSN:2100-014X