Baker, Michael J.Kopp, JoachimLong, Andrew J.2020-11-062020-11-062020Baker, Michael J., Kopp, Joachim and Long, Andrew J.. "Filtered Dark Matter at a First Order Phase Transition." <i>Physical Review Letters,</i> 125, no. 15 (2020) American Physical Society: https://doi.org/10.1103/PhysRevLett.125.151102.https://hdl.handle.net/1911/109521We describe a new mechanism of dark matter production. If dark matter particles acquire mass during a first order phase transition, it is energetically unfavorable for them to enter the expanding bubbles. Instead, most of them are reflected and quickly annihilate away. The bubbles eventually merge as the phase transition completes and only the dark matter particles that have entered the bubbles survive to constitute the observed dark matter today. This mechanism can produce dark matter with masses from the TeV scale to above the PeV scale, surpassing the Griest-Kamionkowski bound.engPublished by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Journal articlehttps://doi.org/10.1103/PhysRevLett.125.151102