We review topics in searches for axion-like-particles (ALPs), covering material that is complementary to other recent reviews. The first half of our review covers ALPs in the extreme environments of neutron star cores, the magnetospheres of highly magnetized neutron stars (magnetars), and in neutron star mergers. The focus is on possible signals of ALPs in the photon spectrum of neutron stars and gravitational wave/electromagnetic signals from neutron star mergers. We then review recent developments in laboratory-produced ALP searches, focusing mainly on accelerator-based facilities including beam-dump type experiments and collider experiments. We provide a general-purpose discussion of the ALP search pipeline from production to detection, in steps, and our discussion is straightforwardly applicable to most beam-dump type and reactor experiments. We end with a selective look at the rapidly developing field of ultralight dark matter, specifically the formation of Bose–Einstein Condensates (BECs). We review the properties of BECs of ultralight dark matter and bridge these properties with developments in numerical simulations, and ultimately with their impact on experimental searches.

中文翻译：

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轴子：从磁星和中子星合并到束流场和 BEC

我们回顾了搜索类轴子粒子 (ALP) 的主题，涵盖与其他近期评论互补的材料。我们回顾的前半部分涵盖了中子星核心极端环境、高磁化中子星（磁星）的磁层以及中子星合并中的 ALP。重点是中子星光子光谱中可能的 ALP 信号和中子星合并产生的引力波/电磁信号。然后，我们回顾了实验室生产的 ALP 搜索的最新进展，主要关注基于加速器的设施，包括光束倾倒型实验和对撞机实验。我们分步提供了从生产到检测的 ALP 搜索管道的通用讨论，我们的讨论直接适用于大多数束流转储类型和反应堆实验。最后，我们选择性地研究了快速发展的超轻暗物质领域，特别是玻色-爱因斯坦凝聚体 (BEC) 的形成。我们回顾了超轻暗物质 BEC 的特性，并将这些特性与数值模拟的发展联系起来，并最终与它们对实验搜索的影响联系起来。