Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal
We present and compare several cosmological constraints on the cross section for elastic scattering between dark matter (DM) and baryons, for cross sections with a range of power-law dependences on the DM-baryon relative velocity v, especially focusing on the case of σ∝v^{-4}. We study constraints s...
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| Format: | Article |
| Language: | English |
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American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/117112 https://orcid.org/0000-0001-9699-9047 |
| _version_ | 1826216462539292672 |
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| author | Slatyer, Tracy Robyn Wu, Chih-Liang |
| author2 | Massachusetts Institute of Technology. Center for Theoretical Physics |
| author_facet | Massachusetts Institute of Technology. Center for Theoretical Physics Slatyer, Tracy Robyn Wu, Chih-Liang |
| author_sort | Slatyer, Tracy Robyn |
| collection | MIT |
| description | We present and compare several cosmological constraints on the cross section for elastic scattering between dark matter (DM) and baryons, for cross sections with a range of power-law dependences on the DM-baryon relative velocity v, especially focusing on the case of σ∝v^{-4}. We study constraints spanning a wide range of epochs in cosmological history, from prerecombination distortions to the blackbody spectrum and anisotropies of the cosmic microwave background (CMB), to modifications to the intergalactic medium temperature and the resulting 21 cm signal, and discuss the allowed signals in the latter channels given the constraints from the former. We improve previous constraints on DM-baryon scattering from the CMB anisotropies, demonstrate via principal component analysis that the effect on the CMB can be written as a simple function of DM mass for v^{-4} scattering, and map out the redshifts dominating this signal. We show that given high-redshift constraints on DM-baryon scattering, a v[superscript -4] scaling of the cross section for light DM would be sufficient to explain the deep 21 cm absorption trough recently claimed by the Experiment to Detect the Reionization Step, if 100% of the DM scatters with baryons; we estimate the minimal necessary velocity scaling and find that it is close to v[superscript -4]. For millicharged DM models proposed to explain the observation, where only a small fraction of the DM interacts, we estimate that a PIXIE-like future experiment measuring CMB spectral distortion could test the relevant parameter space. |
| first_indexed | 2024-09-23T16:48:05Z |
| format | Article |
| id | mit-1721.1/117112 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:48:05Z |
| publishDate | 2018 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1171122022-10-03T08:23:58Z Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal Slatyer, Tracy Robyn Wu, Chih-Liang Massachusetts Institute of Technology. Center for Theoretical Physics Massachusetts Institute of Technology. Department of Physics Slatyer, Tracy Robyn Wu, Chih-Liang We present and compare several cosmological constraints on the cross section for elastic scattering between dark matter (DM) and baryons, for cross sections with a range of power-law dependences on the DM-baryon relative velocity v, especially focusing on the case of σ∝v^{-4}. We study constraints spanning a wide range of epochs in cosmological history, from prerecombination distortions to the blackbody spectrum and anisotropies of the cosmic microwave background (CMB), to modifications to the intergalactic medium temperature and the resulting 21 cm signal, and discuss the allowed signals in the latter channels given the constraints from the former. We improve previous constraints on DM-baryon scattering from the CMB anisotropies, demonstrate via principal component analysis that the effect on the CMB can be written as a simple function of DM mass for v^{-4} scattering, and map out the redshifts dominating this signal. We show that given high-redshift constraints on DM-baryon scattering, a v[superscript -4] scaling of the cross section for light DM would be sufficient to explain the deep 21 cm absorption trough recently claimed by the Experiment to Detect the Reionization Step, if 100% of the DM scatters with baryons; we estimate the minimal necessary velocity scaling and find that it is close to v[superscript -4]. For millicharged DM models proposed to explain the observation, where only a small fraction of the DM interacts, we estimate that a PIXIE-like future experiment measuring CMB spectral distortion could test the relevant parameter space. United States. Department of Energy (Grant DE-SC00012567) United States. Department of Energy (Grant DE-SC0013999) 2018-07-25T15:20:09Z 2018-07-25T15:20:09Z 2018-07 2018-05 2018-07-14T18:00:15Z Article http://purl.org/eprint/type/JournalArticle 2470-0010 2470-0029 http://hdl.handle.net/1721.1/117112 Slatyer, Tracy R. and Chih-Liang Wu. "Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal." Physical Review D 98, 2 (July 2018): 023013 © 2018 American Physical Society https://orcid.org/0000-0001-9699-9047 en http://dx.doi.org/10.1103/PhysRevD.98.023013 Physical Review D Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Slatyer, Tracy Robyn Wu, Chih-Liang Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title | Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title_full | Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title_fullStr | Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title_full_unstemmed | Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title_short | Early-Universe constraints on dark matter-baryon scattering and their implications for a global 21 cm signal |
| title_sort | early universe constraints on dark matter baryon scattering and their implications for a global 21 cm signal |
| url | http://hdl.handle.net/1721.1/117112 https://orcid.org/0000-0001-9699-9047 |
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