Comment: Exact vacuum solution with Hopf structure in general relativity
General Relativity and Quantum Cosmology
2026-03-10 v1
Abstract
Harada's recently announced Kerr-Schild solution of Einstein's equations in general relativity [Phys. Rev. D {\bf 112}, 024020 92025)] is identified as isometric with one of the well-known NUT solutions.
Cite
@article{arxiv.2603.08606,
title = {Comment: Exact vacuum solution with Hopf structure in general relativity},
author = {Malcolm A. H. MacCallum},
journal= {arXiv preprint arXiv:2603.08606},
year = {2026}
}
Comments
2 pages. Submitted as comment to Phys. Rev. D