Equality of ADM Mass and Generalized Komar Energy in Asymptotically-Flat Dynamical Spacetimes

Tuesday 30 Dec 2025, 14:00 → 16:00 Asia/Shanghai

6620 (ITP South Building)

Speaker: 王志伟/Zhi-Wei Wang (University of York)

Abstract: In the framework of General Relativity, the definition and interpretation of energy (mass) remains one of its most profound and enduring challenges. Two of the most widely recognized definitions are the ADM mass and the Komar mass: the ADM mass is defined based on the Hamiltonian principle, while the Komar mass is constructed via Noether's principle. Although their definitional phylosophy are distinct, they have been proven to be completely equivalent in stationary,asymptotically flat spacetimes. However, their specific relationship in dynamic spacetimes has remained unclear for fifty years. Our research focuses on the correlation between ADM energy and generalized Komar mass within asymptotically flat dynamic spacetimes. We demonstrate that a generalized Komar energy, constructed using an appropriately chosen asymptotic timelike vector field, is exactly equivalent to the ADM energy. This result extends the equivalence of ADM and Komar energy to more general dynamic scenarios, providing a powerful analytical tool for addressing energy problems in dynamic spacetimes involving compact objects (such as black holes).

Biography: Zhiwei Wang is a Postdoctoral Researcher at the University of York, UK. He received his PhD from the University of York in August 2020. Subsequently, he conducted postdoctoral research at the University of Lethbridge (Canada), the University of Warwick (UK), and the University of York (UK). His research primarily focuses on theoretical work regarding black hole thermodynamics, dynamic spacetimes, and quantum gravity phenomena. His relevant research results have been published as the first author in journals such as Nature Astronomy, Nature Communications, and Physical Review D..