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Abstract |
To compute properties of phase transitions in condensed matter or the interactions
of elementary particles, quantum field theory is typically solved perturbatively.
This expansion produces divergent series, so the extraction of meaningful results
(resummation) is not straightforward. In fact, very little is known about the
actual asymptotic behaviour of these series.
In this talk, I will introduce a new limit of quantum field theory (the tropical
limit), which is easily computable to very high orders in perturbation theory, yet
at the same time captures the full complexity of subdivergences, renormalization,
and scheme dependence. I will illustrate that the values of Feynman integrals and
their tropical limit are highly correlated. Based on data up to 400 loops, we can
precisely determine the asymptotic growth of the (tropical) beta function in
different renormalization schemes. In particular, we find unexpectedly complicated
instantons, and we confirm the absence of renormalons in the minimal subtraction
scheme. |