Zhang, Cheng-Yong; Tian, Yu; Wu, Xiao-Ning; Zhang, Shao-Jun Entropy of the isolated horizon from the surface term of gravitational action. (English) Zbl 1304.83019 Classical Quantum Gravity 31, No. 19, Article ID 195002, 12 p. (2014). Summary: Starting from the surface term of gravitational action, one can construct a Virasoro algebra with central extension, with which the horizon entropy can be derived using the Cardy formula. This approach provides a new routine for calculating and interpreting the horizon entropy. In this paper, we generalize this approach to a more general case, the isolated horizon, which contains non-stationary spacetimes beyond stationary ones. By imposing appropriate boundary conditions near the horizon, the full set of diffeomorphisms is restricted to a subset where the corresponding Noether charges form a Virasoro algebra with central extension. Then by using the Cardy formula, we can derive the entropy of the isolated horizon. Cited in 1 Document MSC: 83C35 Gravitational waves 83C57 Black holes 83C75 Space-time singularities, cosmic censorship, etc. 94A17 Measures of information, entropy 83C05 Einstein’s equations (general structure, canonical formalism, Cauchy problems) 83C40 Gravitational energy and conservation laws; groups of motions 17B68 Virasoro and related algebras Keywords:entropy; isolated horizon; surface term; gravitational action; Virasoro algebra; Noether charges; Cardy formula PDFBibTeX XMLCite \textit{C.-Y. Zhang} et al., Classical Quantum Gravity 31, No. 19, Article ID 195002, 12 p. (2014; Zbl 1304.83019) Full Text: DOI arXiv