Taming non-analyticities of QFT observables

Abstract Many observables in quantum field theories are involved non-analytic functions of the parameters of the theory. However, it is expected that they are not arbitrarily wild, but rather have only a finite amount of geometric complexity. This expectation has been recently formalized by a tamene...

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Bibliographic Details
Main Authors: Thomas W. Grimm, Giovanni Ravazzini, Mick van Vliet
Format: Article
Language:English
Published: SpringerOpen 2025-02-01
Series:Journal of High Energy Physics
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Online Access:https://doi.org/10.1007/JHEP02(2025)009
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Summary:Abstract Many observables in quantum field theories are involved non-analytic functions of the parameters of the theory. However, it is expected that they are not arbitrarily wild, but rather have only a finite amount of geometric complexity. This expectation has been recently formalized by a tameness principle: physical observables should be definable in o-minimal structures and their sharp refinements. In this work, we show that a broad class of non-analytic partition and correlation functions are tame functions in the o-minimal structure known as ℝ G $$ {\mathbb{R}}_{\mathcal{G}} $$ — the structure defining Gevrey functions. Using a perturbative approach, we expand the observables in asymptotic series in powers of a small coupling constant. Although these series are often divergent, they can be Borel-resummed in the absence of Stokes phenomena to yield the full partition and correlation functions. We show that this makes them definable in ℝ G $$ {\mathbb{R}}_{\mathcal{G}} $$ and provide a number of motivating examples. These include certain 0-dimensional quantum field theories and a set of higher-dimensional quantum field theories that can be analyzed using constructive field theory. Finally, we discuss how the eigenvalues of certain Hamiltonians in quantum mechanics are also definable in ℝ G $$ {\mathbb{R}}_{\mathcal{G}} $$ .
ISSN:1029-8479