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It is often said that the gravitational field has negative energy, and that this negative gravitational energy of all the distant mass exactly cancels the positive mass-energy in the universe.

Why do we think they exactly balance?

A more formal (preferably) mathematical) explanation would be preferred, instead of analogies.

thank you

Qmechanic
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L Turner
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    What do you mean "it is often said"? This sounds like the zero-energy universe model, which is not exactly universally accepted. – ACuriousMind Nov 01 '22 at 00:39
  • I'm not sure where you read this. Probably they are referring to the 'effective stress-energy tensor'=$T_{ab}-\frac{1}{\kappa}G_{ab}=0$ (from Einstein's field equation). Einstein tensor $G_{ab}$ is not the stress energy tensor for gravity. Total energy need not be conserved in a generic case. I'll probably post an answer sometime later – KP99 Nov 01 '22 at 01:31
  • Possible duplicates: https://physics.stackexchange.com/q/2838/2451 and links therein. – Qmechanic Nov 01 '22 at 05:03
  • Energy is the ability of a system to perform work on another system. What is that "other system" that the universe is supposed to perform work on? If there is no such system, then what is the phrase "energy of the universe" supposed to mean? – FlatterMann Nov 01 '22 at 06:42

  • What do you mean "it is often said"? This sounds like the zero-energy universe model, which is not exactly universally accepted.

     – L Turner Nov 01 '22 at 11:35

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