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arXiv · 2205.00712

Dark sector domain walls could explain the observed planes of satellites

Aneesh P. Naik·Clare Burrage
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Abstract

The observed `planes of satellites' around the Milky Way and other nearby galaxies are notoriously difficult to explain under the $\Lambda$CDM paradigm. Here, we propose an alternative solution: domain walls arising in theories with symmetry-breaking scalar fields coupled to matter. Because of the matter coupling, satellite galaxies experience fifth forces as they pass through domain walls, leading to a subset of satellites with orbits confined to the domain wall plane. We demonstrate this effect using simple simulations of a toy model comprising point-like satellites and an infinite domain wall, and explore the efficacy of various planarity metrics in detecting this effect. We believe this is the first potential `new physics' explanation for the observed planes of satellites which does not do away with dark matter.

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Aneesh P. Naik, Clare Burrage. 2022-05-02. Dark sector domain walls could explain the observed planes of satellites. https://doi.org/10.1088/1475-7516%2F2022%2F08%2F020

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