2007/04/30 by Yungui Gong, Anzhong Wang · 1 citation
Physics and Astronomy · #Apparent horizon #Black Holes and Theoretical Physics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Event horizon #First law of thermodynamics #Friedmann equations #Gravitation #Horizon #Mathematical physics #Physics #Quantum mechanics #Relativity and Gravitational Theory #Second law of thermodynamics #Thermodynamics #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevlett.99.211301
published as Phys.Rev.Lett.99:211301,2007 · no figures, V2: re-organized and re-writtend, main results and conclusion unchanged, Phys. Rev. Lett. in press
arxiv created 2007/11/14 · openalex publication_date 2007/11/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
With the help of a masslike function which has a dimension of energy and is equal to the Misner-Sharp mass at the apparent horizon, we show that the first law of thermodynamics of the apparent horizon dE=T(A)dS(A) can be derived from the Friedmann equation in various theories of gravity, including the Einstein, Lovelock, nonlinear, and scalar-tensor theories. This result strongly suggests that the relationship between the first law of thermodynamics of the apparent horizon and the Friedmann equation is not just a simple coincidence, but rather a more profound physical connection.