2016/05/03 by Hang Liu, Xin-He Meng, Xin-he Meng +2
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Black hole thermodynamics #Cosmology and Gravitation Theories #Dilaton #Einstein #Entropy (arrow of time) #Galaxies: Formation, Evolution, Phenomena #Mathematical physics #Mathematics #Physics #Statistical physics #Theoretical physics #Thermodynamics #gr-qc #hep-th
paper · pdf · doi:10.1209/0295-5075/119/20003
published as Europhys.Lett. 119 (2017) no.2, 20003
arxiv created 2016/05/03 · openalex publication_date 2017/07/01 · arxiv updated 2017/10/09 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/30
We first give some entropy relations for black holes in modified gravity models, which are introduced as an elegant technique trick for handling various entropy bounds. For these entropy relations, some are mass-independent and universal, while others are not. Then we study the entropy bound of horizons in modified gravity, including Horava-Lifshitz gravity, massive gravity and Einstein-dilaton gravity. We focus on black holes with two or three physical horizons, containing the event horizon, Cauchy horizon and negative horizon which is physical for the observers in the negative radial coordinate region. In these modified gravity, entropy bounds are geometrical bounds which are related close to the cosmological radius for asymptotically (A)dS black holes, while they are Penrose-like inequalities for asymptotically flat black holes. Moreover, they depend on the constants characterizing the strength of modified terms in the actions. We also present the first law of thermodynamics and Smarr relations for horizons.