Derivation of the null energy condition

Maulik Parikh, Jan Pieter Van Der Schaar

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


We derive the null energy condition, understood as a constraint on the Einstein-frame Ricci tensor, from world sheet string theory. For a closed bosonic string propagating in a curved geometry, the spacetime interpretation of the Virasoro constraint condition is precisely the null energy condition, to leading nontrivial order in the α′ expansion. Thus the deepest origin of the null energy condition lies in world sheet diffeomorphism invariance.

Original languageEnglish (US)
Article number084002
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number8
StatePublished - Apr 3 2015

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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