Abstract
In this article, we elaborate further on the varLambda CDM “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 varLambda CDM. Including GRBs in the analysis we find a tension, which lies between 2sigma and 3sigma levels respectively. Finally, we find that at high redshifts (z>1) the corresponding cosmokinetic parameters significantly deviate from those of varLambda CDM, hence the possibility of new Physics is not precluded by the present analysis.
Highlights
Since the discovery of the accelerated expansion of the Universe from the Supernovae type Ia (SNIa) data [3,4], the combined analysis of various cosmological probes, including those of Cosmic Microwave Background (CMB) [5,6,7], Baryon Acoustic Oscillation (BAO) [8,9,10,11,12,13,14] and cosmic chronometers [15] confirms the aforementioned dynamical result, namely that currently the Universe accelerates
For the usual standard candles (SNIa data) and for the combination SNIa/QSOs we find that the cosmokinetic parameters (q0, j0) extracted from the Gaussian process are consistent with ΛCDM
It is well known that the concordance ΛCDM model fits accurately the current cosmological data [7], it has been proposed that the model is not without its problems
Summary
Since the discovery of the accelerated expansion of the Universe from the Supernovae type Ia (SNIa) data [3,4], the combined analysis of various cosmological probes, including those of Cosmic Microwave Background (CMB) [5,6,7], Baryon Acoustic Oscillation (BAO) [8,9,10,11,12,13,14] and cosmic chronometers [15] confirms the aforementioned dynamical result, namely that currently the Universe accelerates. Despite the fact that the ΛCDM model is found to be in a very good agreement with the majority of cosmological data [7], the model seems to be currently in tension with some recent measurements [32,33,34,35], related with the Hubble constant H0 and the present value of the mass variance at 8h−1Mpc, namely σ8. In the light of the latter results, a heated debate is taking place in the literature and the aim of the present article is to contribute to this debate
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