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UID:20260525T154449EDT-0530j8m2sU@132.216.98.100
DTSTAMP:20260525T194449Z
DESCRIPTION:Instanton calculus in quantum mechanics: Feynman diagrams and d
 ivergent series.\n\nIn this talk we discuss quantum mechanical problems\, 
 the double-well and sine-Gordon potentials\, for which perturbation theory
  fails to explain physical properties even qualitatively. We then explain 
 how non-perturbative effects can be obtained by instanton calculus. The co
 rresponding Feynman diagrams (integrals) are used for the calculation of t
 he tunneling amplitude up to the three-loop order. Unlike the two-loop con
 tribution where all involved Feynman integrals are rational numbers\, we w
 ill show that in the three-loop case they contain irrational contributions
  as well.\n
DTSTART:20170424T193000Z
DTEND:20170425T203000Z
LOCATION:Room 4336\, CA\, QC\, Montreal\, H3T 1J4\, Pavillon André-Aisensta
 dt\, 2920\, Chemin de la tour\, 5th floor
SUMMARY:Adrian Escobar\, CRM
URL:https://www.mcgill.ca/mathstat/channels/event/adrian-escobar-crm-267815
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