On dataset tensions and signatures of new cosmological physics
| Autor: | Cortês, Marina, Liddle, Andrew R. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society 531 (2024) L52-L56 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnrasl/slae030 |
| Popis: | Can new cosmic physics be uncovered through tensions amongst datasets? Tensions in parameter determinations amongst different types of cosmological observation, especially the `Hubble tension' between probes of the expansion rate, have been invoked as possible indicators of new physics, requiring extension of the $\Lambda$CDM paradigm to resolve. Within a fully Bayesian framework, we show that the standard tension metric gives only part of the updating of model probabilities, supplying a data co-dependence term that must be combined with the Bayes factors of individual datasets. This shows that, on its own, a reduction of dataset tension under an extension to $\Lambda$CDM is insufficient to demonstrate that the extended model is favoured. Any analysis that claims evidence for new physics {\it solely} on the basis of alleviating dataset tensions should be considered incomplete and suspect. We describe the implications of our results for the interpretation of the Hubble tension. Comment: 5 pages, matches MNRAS accepted version, corrections and updates to discussion of systematics, and other minor changes |
| Databáze: | arXiv |
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