García Río, EduardoMariño-Villar, RodrigoVázquez Abal, María ElenaVázquez Lorenzo, Ramón2022-08-232022-08-232021Math Meth Appl Sci. 2021;44:14316–14327. https://doi.org/10.1002/mma.7698http://hdl.handle.net/10347/29126We classify homogeneous four-dimensional manifolds satisfying a curvature condition which naturally generalizes the Einstein one. Our work leads to new examples of self-similar solutions of the two-loop renormalization group flowengThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2021 The Authors. Mathematical Methods in the Applied Sciences published by John Wiley & Sons Ltdhttp://creativecommons.org/licenses/by-nc-nd/4.0/Critical metricEinstein metricHomogeneous spaceRicci solitonjournal article10.1002/mma.76981099-1476open access