Modified Friedmann equations and fractal black hole thermodynamics (Q6565001)

This paper is concerned with the thermodynamics of a fractal universe, which arises from a modified gravity theory incorporating fractal functions [\textit{G. Calcagni}, J. High Energy Phys. 2010, No. 3, Paper No. 120, 38 p. (2010; Zbl 1271.83032)]. The nonequilibrium thermodynamics of the cosmological horizon is explored, including the generalized second law, building on previous work [\textit{A. Sheykhi} et al., Phys. Lett., B 718, No. 4--5, 1203--1207 (2013; Zbl 1372.83095)]. A modified Friedmann equation is then derived from the first law of thermodynamics, and the authors find that late-time acceleration is feasible in this framework.