Evolution and metric signature change of maximally symmetric spaces under the Ricci flow R. Cartas-Fuentevilla, A. Herrera-Aguilar and J. A. Olvera-Santamaría Eur. Phys. J. Plus, 133 6 (2018) 235 Published online: 22 June 2018 DOI: 10.1140/epjp/i2018-12067-1