Does Λ CDM really be in tension with the Hubble diagram data?

Abstract

In this article, we elaborate further on the ΛCDM “tension”, suggested recently by the authors Lusso et al. (Astron Astrophys 628:L4, 2019) and Risaliti and Lusso (Nat Astron 3(3):272, 2019). We combine Supernovae type Ia (SNIa) with quasars (QSO) and Gamma Ray Bursts (GRB) data in order to reconstruct in a model independent way the Hubble relation to as high redshifts as possible. Specifically, in the case of either SNIa or SNIa/QSO data we find that the current values of the cosmokinetic parameters extracted from the Gaussian process are consistent with those of ΛCDM. Including GRBs in the analysis we find a tension, which lies between 2 σ and 3 σ levels respectively. Finally, we find that at high redshifts (z> 1) the corresponding cosmokinetic parameters significantly deviate from those of ΛCDM, hence the possibility of new Physics is not precluded by the present analysis.