Matt McIrvin on Nostr: General Relativity is different from other field theories in that, usually, you can ...

General Relativity is different from other field theories in that, usually, you can define a localized stress-energy tensor for the field itself (up to ambiguities that don't affect conservation laws). But in GR, if you attempt it, the quantity is coordinate-dependent and cannot be made covariant. So you can make the gravitational stress-energy in any local area disappear with a choice of coordinates. It's slippery.