On relativistic generalization of Perelman’s W-entropy and thermodynamic description of gravitational fields and cosmologyVyacheslav Ruchin, Olivia Vacaru and Sergiu I. VacaruEur. Phys. J. C, 77 3 (2017) 184DOI: https://doi.org/10.1140/epjc/s10052-017-4712-1