18/07/2016, 15:10 — 15:50 — Amphitheatre Ea1, North Tower, IST
Michael Borinsky, Humboldt University Berlin

Asymptotic Calculus for Combinatorial Dyson-Schwinger Equations

Most perturbative expansions in QFT are asymptotic series. This divergence is believed to be dominated by the factorial growth of the number of Feynman diagrams. Asymptotic expansions of this type have many interesting properties. They form a subring of the ring of formal power series, which is also closed under composition and inversion. On this space a derivative can be defined which fulfills Leibniz and chain rules. This asymptotic calculus can be used to obtain asymptotic expansions of expressions which are only given implicitly, for instance by functional or differential equations.

See also

R-borinsky.pdf