In this article I bring the recent philosophical literature on theoretical equivalence to bear on dualities in physics. Focusing on electromagnetic duality, which is a simple example of S-duality in string theory, I show that the duality fits naturally into at least one framework for assessing equivalence—that of categorical equivalence—but that it fails to meet a necessary condition for equivalence on that account. The reason is that the duality does not preserve “empirical content” in the required sense; instead, it takes models to models with “dual” empirical content. I conclude by discussing how one might react to this.

中文翻译：

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电磁学中的等价性和对偶性

在这篇文章中，我将最近关于理论等价的哲学文献与物理学中的二元性联系起来。关注电磁对偶性，这是弦理论中 S 对偶性的一个简单例子，我表明对偶性自然地适合至少一个评估等价的框架——分类等价的框架——但它未能满足等价的必要条件在那个帐户上。原因是二元性没有保留所需意义上的“经验内容”；相反，它将模型用于具有“双重”经验内容的模型。最后，我将讨论人们对此的反应。