Séminaire / Seminar GReCO |
| « The distance duality relation: violations, constraints and biases » |
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Natalie Hogg |
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We live in the era of precision cosmology, but how can we be sure that we are not losing out on accuracy and becoming susceptible to bias when striving for ever-greater precision in our cosmological measurements? To illustrate this question, in this talk I will present forecast BAO, SNIa and standard siren constraints on a violation of the strict relationship between luminosity and angular diameter distances, known as the distance duality relation (DDR). I will show how such constraints can be biased in the presence of a generic modified gravity model and how such a bias can be correctly accounted for in similar analyses. I will then go on to show how, in combination with Hubble's law, the distance duality relation can be used as a consistency check for beyond-LCDM cosmological models, revealing a 2s discrepancy between the validity of the DDR and the latest Cepheid-calibrated SNIa measurement of H0.
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lundi 4 avril 2022 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |