Cosmography and flat $\Lambda$CDM tensions at high redshift

Tao Yang, Aritra Banerjee, Eoin Ó Colgáin

Risaliti, Lusso \& collaborators have constructed a high-redshift Hubble diagram of supernovae (SNe); quasars (QSO) and gamma-ray bursts (GRB) that shows a "$\sim 4\sigma$ tension w…