QED perturbation theory has been conjectured to break down in sufficiently strong backgrounds, obstructing the analysis of strong-field physics. We show that the breakdown occurs even in classical electrodynamics, at lower field strengths than previously considered, and that it may be cured by resummation. As a consequence, an analogous resummation is required in QED. A detailed investigation shows, for a range of observables, that unitarity removes diagrams previously believed to be responsible for the breakdown of QED perturbation theory.

中文翻译：

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强场 QED 的经典恢复和分解

已经推测 QED 微扰理论在足够强的背景下崩溃，阻碍了强场物理的分析。我们表明，即使在经典电动力学中，在场强低于先前考虑的情况下也会发生击穿，并且可以通过恢复来治愈。因此，在 QED 中需要类似的恢复。一项详细的调查表明，对于一系列可观测的，单一性消除了以前认为是 QED 扰动理论崩溃的原因的图表。