It is widely believed and in part established that exact global symmetries are inconsistent with quantum gravity. One then expects that approximate global symmetries can be quantitatively constrained by quantum gravity or swampland arguments. We provide such a bound for an important class of global symmetries: Those arising from a gauged $U(1)$ with the vector made massive via Higgsing with an axion. The latter necessarily couples to instantons, and their action can be constrained, using both the electric and magnetic version of the axionic weak gravity conjecture, in terms of the cutoff of the theory. As a result, instanton-induced symmetry breaking operators with a suppression factor not smaller than $\exp (-M_{\mathrm{P}}^2/{\mathrm{\Lambda }}^2)$ are present, where Λ is a cutoff of the 4d effective theory. We provide a general argument and clarify the meaning of Λ. Simple 4d and 5d models are presented to illustrate this, and we recall that this is the standard way in which things work out in string compactifications with brane instantons. The relation of our constraint to bounds that can be derived from wormholes or gravitational instantons and to those motivated by black-hole effects at finite temperature are discussed, and we present a generalization of the Giddings-Strominger wormhole solution to the case of a gauge-derived $U(1)$ global symmetry. Finally, we discuss potential loopholes to our arguments.

人们普遍认为并部分确定确切的整体对称性与量子引力不一致。然后人们期望近似的全局对称性可以被量子引力或沼泽地论证定量地限制。我们为一类重要的全局对称性提供了这样的约束：$ü（\mathrm{1个}）$通过轴切希格斯效应使向量变得庞大。后者必定会耦合到瞬时子，并且根据理论的截断，可以使用电离子形式和磁性形式的两性弱重力猜想来限制它们的作用。结果，抑制因子不小于的瞬时子对称对称破坏算子$\mathrm{经验值}（-{\mathrm{中号}}_{\mathrm{P}}^2/{\mathrm{\Lambda }}^2）$存在，其中Λ是4d有效理论的截止值。我们提供一个一般性的论点，并阐明Λ的含义。给出了简单的4d和5d模型来说明这一点，我们还记得这是使用brane实例化字符串压缩中的标准方法。讨论了我们的约束与可从虫洞或引力瞬时子得出的界限以及在有限温度下受黑洞效应激发的界限之间的关系，并且我们针对规范的情况对Giddings-Strominger虫洞解决方案进行了概括派生的$ü（\mathrm{1个}）$全局对称。最后，我们讨论了潜在的漏洞。