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| Main Authors: | , , , , |
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| Format: | Preprint |
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2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2505.24543 |
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| _version_ | 1866909629280157696 |
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| author | Avila, Felipe Rivera, Alexander Bonilla Nunes, Rafael C. Holanda, R. F. L. Bernui, Armando |
| author_facet | Avila, Felipe Rivera, Alexander Bonilla Nunes, Rafael C. Holanda, R. F. L. Bernui, Armando |
| contents | In this work, we perform a statistical inference of the classical background law governing the evolution of the temperature of the cosmic microwave background radiation (CMB), given by $T_{\rm CMB}(z) = T_0(1 + z)$. To this end, we employ Gaussian Process (GP) regression techniques to reconstruct the temperature evolution based on two observational datasets: (i) CMB-Sunyaev-Zel'dovich (SZ) cluster measurements and (ii) CMB-interstellar medium (ISM) interaction data. Our analysis reveals interesting results that may suggest potential deviations from the standard temperature-redshift relation, particularly at low redshifts ($z < 0.5$), where discrepancies up to $\sim$2$σ$ are observed. Additionally, we identify a mild but noteworthy tension, also at the $\sim$2$σ$ level, between our GP inferred value of the present-day CMB temperature, $T_{\rm CMB}(z=0)$, and the precise direct measurement from the COBE/FIRAS experiment. We also explore possible phenomenological implications of our findings, including interpretations associated with possible variations in fundamental constants, such as the fine-structure constant $α$, which could provide a physical explanation for the observed deviations at low redshift. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_24543 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Revisiting the temperature evolution law of the CMB with gaussian processes Avila, Felipe Rivera, Alexander Bonilla Nunes, Rafael C. Holanda, R. F. L. Bernui, Armando Cosmology and Nongalactic Astrophysics In this work, we perform a statistical inference of the classical background law governing the evolution of the temperature of the cosmic microwave background radiation (CMB), given by $T_{\rm CMB}(z) = T_0(1 + z)$. To this end, we employ Gaussian Process (GP) regression techniques to reconstruct the temperature evolution based on two observational datasets: (i) CMB-Sunyaev-Zel'dovich (SZ) cluster measurements and (ii) CMB-interstellar medium (ISM) interaction data. Our analysis reveals interesting results that may suggest potential deviations from the standard temperature-redshift relation, particularly at low redshifts ($z < 0.5$), where discrepancies up to $\sim$2$σ$ are observed. Additionally, we identify a mild but noteworthy tension, also at the $\sim$2$σ$ level, between our GP inferred value of the present-day CMB temperature, $T_{\rm CMB}(z=0)$, and the precise direct measurement from the COBE/FIRAS experiment. We also explore possible phenomenological implications of our findings, including interpretations associated with possible variations in fundamental constants, such as the fine-structure constant $α$, which could provide a physical explanation for the observed deviations at low redshift. |
| title | Revisiting the temperature evolution law of the CMB with gaussian processes |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2505.24543 |