标题： 弯曲时空中的Kerr-Schild双复制 显示英文标题

标题： The Kerr-Schild double copy in curved spacetime

摘要： 双复制是规范理论和引力理论中散射幅度之间被广泛研究的关系，后来已被扩展到经典场解。在几乎所有以前的例子中，引力子场都是在闵可夫斯基空间周围定义的。最近，有人提出可以在非平凡背景上定义引力子的情况下建立双复制。我们从经典双复制的角度来研究这个想法。首先，我们使用Kerr-Schild时空在弯曲空间中构造引力子解，作为在非零规范背景上的规范场的双复制。接下来，我们发现可以将这些情况重新解释为在非闵可夫斯基背景上的引力子，其单复制是在同一背景时空中的规范场。这种类型的双复制即使当背景不是Kerr-Schild形式时仍然存在，我们提供了涉及共形平坦度规的例子。我们的结果将有助于扩展双复制的适用范围，包括可能的宇宙学应用。 显示英文摘要

摘要： The double copy is a much-studied relationship between scattering amplitudes in gauge and gravity theories, that has subsequently been extended to classical field solutions. In nearly all previous examples, the graviton field is defined around Minkowski space. Recently, it has been suggested that one may set up a double copy for gravitons defined around a non-trivial background. We investigate this idea from the point of view of the classical double copy. First, we use Kerr-Schild spacetimes to construct graviton solutions in curved space, as double copies of gauge fields on non-zero gauge backgrounds. Next, we find that we can reinterpret such cases in terms of a graviton on a non-Minkowski background, whose single copy is a gauge field in the same background spacetime. The latter type of double copy persists even when the background is not of Kerr-Schild form, and we provide examples involving conformally flat metrics. Our results will be useful in extending the remit of the double copy, including to possible cosmological applications.