Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe.
The question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology but has not yet been answered decisively. Surprisingly, neither an isotropic primary cosmic microwave background (CMB) nor combined observations of luminosity d...
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| Format: | Journal article |
| Language: | English |
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2012
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| _version_ | 1797066427417493504 |
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| author | Clifton, T Clarkson, C Bull, P |
| author_facet | Clifton, T Clarkson, C Bull, P |
| author_sort | Clifton, T |
| collection | OXFORD |
| description | The question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology but has not yet been answered decisively. Surprisingly, neither an isotropic primary cosmic microwave background (CMB) nor combined observations of luminosity distances and galaxy number counts are sufficient to establish such a result. The inclusion of the Sunyaev-Zel'dovich effect in CMB observations, however, dramatically improves this situation. We show that even a solitary observer who sees an isotropic blackbody CMB can conclude that the Universe is homogeneous and isotropic in their causal past when the Sunyaev-Zel'dovich effect is present. Critically, however, the CMB must either be viewed for an extended period of time, or CMB photons that have scattered more than once must be detected. This result provides a theoretical underpinning for testing the cosmological principle with observations of the CMB alone. |
| first_indexed | 2024-03-06T21:41:55Z |
| format | Journal article |
| id | oxford-uuid:48361bf4-fe8b-474d-af85-3f515ba7ad23 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:41:55Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | oxford-uuid:48361bf4-fe8b-474d-af85-3f515ba7ad232022-03-26T15:24:30ZIsotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:48361bf4-fe8b-474d-af85-3f515ba7ad23EnglishSymplectic Elements at Oxford2012Clifton, TClarkson, CBull, PThe question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology but has not yet been answered decisively. Surprisingly, neither an isotropic primary cosmic microwave background (CMB) nor combined observations of luminosity distances and galaxy number counts are sufficient to establish such a result. The inclusion of the Sunyaev-Zel'dovich effect in CMB observations, however, dramatically improves this situation. We show that even a solitary observer who sees an isotropic blackbody CMB can conclude that the Universe is homogeneous and isotropic in their causal past when the Sunyaev-Zel'dovich effect is present. Critically, however, the CMB must either be viewed for an extended period of time, or CMB photons that have scattered more than once must be detected. This result provides a theoretical underpinning for testing the cosmological principle with observations of the CMB alone. |
| spellingShingle | Clifton, T Clarkson, C Bull, P Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title | Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title_full | Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title_fullStr | Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title_full_unstemmed | Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title_short | Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe. |
| title_sort | isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe |
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