Resurgent transseries $\&$ Dyson-Schwinger equations

TL;DR

This paper uses resurgent transseries to analyze Dyson-Schwinger equations in quantum field theories, revealing patterns of resurgence and limitations of current ansatzes in capturing nonperturbative effects.

Contribution

It introduces an algebraic method for studying transseries solutions to Dyson-Schwinger equations and highlights the challenges in capturing nonperturbative sectors.

Findings

Resurgence pattern observed between perturbative and nonperturbative sectors.

Current ansatz leads to trivial solutions with vanishing nonperturbative sectors.

Provides a mathematical introduction to grid-based transseries.

Abstract

We employ resurgent transseries as algebraic tools to investigate two self-consistent Dyson-Schwinger equations, one in Yukawa theory and one in quantum electrodynamics. After a brief but pedagogical review, we derive fixed point equations for the associated anomalous dimensions and insert a moderately generic log-free transseries ansatz to study the possible strictures imposed. While proceeding in various stages, we develop an algebraic method to keep track of the transseries' coefficients. We explore what conditions must be violated in order to stay clear of fixed point theorems to eschew a unique solution, if so desired, as we explain. An interesting find is that the flow of data between the different sectors of the transseries shows a pattern typical of resurgence, ie the phenomenon that the perturbative sector of the transseries talks to the nonperturbative ones in a one-way fashion. However, our ansatz is not exotic enough as it leads to trivial solutions with vanishing nonperturbative sectors, even when logarithmic monomials are included. We see our result as a harbinger of what future work might reveal about the transseries representations of observables in fully renormalised four-dimensional quantum field theories and adduce a tentative yet to our mind weighty argument as to why one should not expect otherwise. This paper is considerably self-contained. Readers with little prior knowledge are let in on the basic reasons why perturbative series in quantum field theory eventually require an upgrade to transseries. Furthermore, in order to acquaint the reader with the language utilised extensively in this work, we also provide a concise mathematical introduction to grid-based transeries.