Energy-momentum of isolated systems cannot be null

Abhay Ashtekar, Gary T. Horowitz

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


It is shown that neither the ADM nor the Bondi four-momentum of an isolated system in general relativity can be null. This strengthens recent results on positivity of energy by showing that the total four-moemtum must be strictly timelike (and future directed).

Original languageEnglish (US)
Pages (from-to)181-184
Number of pages4
JournalPhysics Letters A
Issue number4
StatePublished - May 10 1982

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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