Physics Letters B (Jul 2021)

From perturbative to non-perturbative in the O(4) sigma model

  • Michael C. Abbott,
  • Zoltán Bajnok,
  • János Balog,
  • Árpád Hegedűs

Journal volume & issue
Vol. 818
p. 136369

Abstract

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We study the resurgent trans-series for the free energy of the two-dimensional O(4) sigma model in a magnetic field. Exploiting integrability, we obtain very high-order perturbative data, from which we can explore non-perturbative sectors. We are able to determine exactly the leading real-valued exponentially small terms, which we check against the direct numerical solution of the exact integral equation, and find complete agreement.