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arXiv · 2406.12051

Unregulated Divergences of Feynman Integrals

Wen Chen
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Abstract

Feynman integrals can be expanded asymptotically with respect to some small parameters at the integrand level, a technique known as the expansion by regions. A naive expansion by regions may break down due to divergences not regulated by the spacetime dimension, exemplified by the rapidity divergences. A criterion to identify unregulated divergences is provided in this article. The analysis is conducted using both parametric and Mellin-Barnes representations, leading to a consistent conclusion. Based on this analysis, it is proven that the presence of unregulated divergences implies the degeneracies of regions.

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Wen Chen. 2024-06-17. Unregulated Divergences of Feynman Integrals. https://doi.org/10.1016/j.physletb.2025.139299

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