Exact null octagon

A. V. Belitsky, G. P. Korchemsky

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


We consider the so-called simplest correlation function of four infinitely heavy half-BPS operators in planar N = 4 SYM in the limit when the operators are light-like separated in a sequential manner. We find a closed-form expression for the correlation function in this limit as a function of the ’t Hooft coupling and residual cross ratios. Our analysis heavily relies on the factorization of the correlation function into the product of null octagons and on the recently established determinant representation for the latter. We show that the null octagon is given by a Fredholm determinant of a certain integral operator which has a striking similarity to those previously encountered in the study of two-point correlation functions in exactly solvable models at finite temperature and of level spacing distributions in random matrices. This allows us to compute the null octagon exactly by employing a method of differential equations.

Original languageEnglish (US)
Article number70
JournalJournal of High Energy Physics
Issue number5
StatePublished - May 1 2020


  • Conformal Field Theory
  • Integrable Field Theories
  • Supersymmetric Gauge Theory

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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