{ "id": "2104.03805", "version": "v1", "published": "2021-04-08T14:31:25.000Z", "updated": "2021-04-08T14:31:25.000Z", "title": "Light-like parallel vector fields and Einstein equations of gravity", "authors": [ "Isidore Mahara", "Célestin Kurujyibwami", "Venuste Nyagahakwa" ], "categories": [ "math-ph", "math.MP" ], "abstract": "We prove that, contrary to the situation with time-like and space-like parallel vector fields, there are real gravitational fields satisfying Einsteins equations of gravity and admitting nontrivial light-like parallel vector fields; we solve completely the field equations under this geometric constraint and obtain through Bianchi identities an interesting property for the Riemann curvature tensor corresponding with a real gravitational field admitting a nontrivial parallel vector field. The solutions we obtained turn out to be generically wave-like and then we prove by a geometric method that this class of solutions is quite different from the class of solutions corresponding with spherical waves.", "revisions": [ { "version": "v1", "updated": "2021-04-08T14:31:25.000Z" } ], "analyses": { "keywords": [ "einstein equations", "fields satisfying einsteins equations", "gravitational fields satisfying einsteins", "real gravitational field", "nontrivial light-like parallel vector fields" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }