The Ashtekar-Hansen universal structure at spatial infinity is weakly pseudo-Carrollian
arXiv:1902.09170
Abstract
It is shown that Ashtekar and Hansens's Universal Structure at Spatial Infinity (SPI), which has recently be used to establish the conservation of supercharges from past null infity to future null infinity, is an example of a (pseudo-) Carollian structure. The relation to Kinematic Algebras is clarified.
Appendix deleted and typos corrected