In the case of Komar mass, we can express the mass as an integral of ##\rho + 3P##, so we can meaningful divide the total mass (or energy) of a system into the contribution due to each part, just by integrating over that spatial part of the system.(adsbygoogle = window.adsbygoogle || []).push({});

What happens if we try to do this with other definitions of mass, say the ADM or Bondi mass? My overall impression is that it can't be done, but I don't have a specific reference for this, so I want to be cautious about saying it cant be done.

I suppose I'm open to general ways of partitioning the mass, and not just my suggested approach of integrating some (pseudo) tensor of some sort over a spatial region.

One obstacle that comes to mind with psuedotensors is the obvious issue of the gauge degree of freedom affecting the subdivision process. But this seems lacking as a proof of impossibility, at least without an example illustrating different "partitioning".

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# Assigning energy (and maybe mometum) to part of a system in GR.

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