https://neckpinch.com/authors/giovanni-calvaruso/New arXiv papers by Giovanni Calvaruso, from Neckpinch Tue, 03 Nov 2026 08:41:12 GMT https://neckpinch.com/papers/2511.06923/arxiv:2511.06923Mon, 10 Nov 2025 00:00:00 GMTGiovanni Calvaruso, Lorenzo Pellegrino, Amirhesam Zaeim — In the framework of the study of homogeneous Lorentzian three-manifolds, we consider here the only class of examples which admit a four-dimensional group of isometries but are neither Lorentzian Bianchi-Cartan-Vranceanu spaces nor plane waves. We obtain an explicit description in global coordinates of these special homogeneous Lorentzian manifolds. We then prove that all such examples are non-gradient expanding Ricci solitons.Ricci solitons3-manifolds4-manifoldsHomogeneous spacesPhysics