Abstract:
This paper studies three-dimensional Lie groups with left-invariant Lorentz metric and almost harmonic (i.e., having curl and divergence zero) Schouten–Weyl tensor. Moreover, by using the convolution of the Schouten-Weyl tensor in the direction of any vector, we define an antisymmetric $2$-tensor and study the structure of the three-dimensional Lie groups and algebras with left-invariant Lorentz metric for which this tensor is harmonic.
Keywords:Lie groups and algebras, left-invariant Lorentz metrics, harmonic tensor, Schouten–Weyl tensor.