http://arxiv.org/abs/1911.01681
Recently constructed high-redshift Hubble diagrams of supernovae, quasars and gamma-ray bursts show $4 \, \sigma$ deviations from flat $\Lambda$CDM, where the discrepancies are observed in cosmographic expansions. In this note, we show that existing approaches to high-redshift cosmography can lead to “tensions” that are simply an artifact of the expansions, even if the underlying model is fully consistent with flat $\Lambda$CDM. Thus, in this note we revisit the $4 \, \sigma$ tensions to ascertain if results have been impacted by the cosmography. In the process, we find that the quasar data, which has been calibrated by external Type Ia supernovae, is surprisingly inconsistent with both supernovae and gamma-ray bursts to the point that combining the datasets is questionable. Results based on cosmography only appear to mask more significant tensions.
T. Yang, A. Banerjee and E. Colgáin
Wed, 6 Nov 19
43/57
Comments: 6 pages, 8 figures. Comments welcome!
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