2005/07/27 by Theo M. Nieuwenhuizen, Th. M. Nieuwenhuizen, Nieuwenhuizen, Th. M. +3
Physics and Astronomy · #Astrophysics (astro-ph) #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #Quantum Physics (quant-ph) #Statistical Mechanics (cond-mat.stat-mech) #astro-ph #cond-mat.stat-mech #gr-qc #hep-th #quant-ph
paper · pdf · doi:10.48550/arxiv.hep-th/0507272
8 pages
arxiv created 2005/07/27 · openalex publication_date 2005/07/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In a recent paper Hawking has argued that there is no information loss in black holes in asymptotically AdS spacetimes. We remind that there are several types of information (entropy) in statistical physics -- fine grained (microscopic) and coarse grained (macroscopic) ones which behave differently under unitary evolution. We suggest that the coarse grained information of the rest of the Universe is lost while fine grained information is preserved. A possibility to develop in quantum gravity an analogue of the Bogoliubov derivation of the irreversible Boltzmann and Navier - Stokes equations from the reversible mechanical equations is discussed.