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SUMMARY:Zoltan Bajnok (Wigner Institute)
DTSTART:20211012T080000Z
DTEND:20211012T090000Z
DTSTAMP:20260423T021011Z
UID:Sem21/2
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/Sem21/2/">Fr
 om perturbative to non-perturbative in the O(4) sigma model</a>\nby Zoltan
  Bajnok (Wigner Institute) as part of SEU Yau Center Theoretical Physics S
 eminars 2021\n\n\nAbstract\nIs it possible to derive non-perturbative cont
 ributions in a quantum field theory knowing only the perturbative coeffici
 ents? We answer this question affirmatively based on the careful analysis 
 of the integrable two dimensional O(4) sigma model. We investigate its gro
 und state energy in a magnetic field\, for which integrability provides an
  exact linear integral equation. By cleverly expanding this equation we co
 uld calculate a large number of very precise\, factorially growing perturb
 ative coefficients. By investigating their asymptotical behaviour on the B
 orel plane we managed to reveal a nice resurgence structure leading to the
  first few exponentially suppressed non-perturbative terms of the ambiguit
 y free trans-series. We checked our results against the direct numerical s
 olution of the exact integral equation and find complete agreement. (based
  on 2011.12254 and 2011.09897)\n
LOCATION:https://researchseminars.org/talk/Sem21/2/
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