Hubble Diagram Test of SN1a Supernovae and High Redshift Gamma Ray Bursts

Hubble diagrams are examined for SN1a supernovae in the redshift range z = 0.01–1.3 and for gamma ray bursts in the range z = 0.034–8.1. It is shown that in the low redshift range, the Hubble diagram shows an innate equivocality between the ΛCDM and the tired light model. This means that the strong agreement between the z/µ data, calculated with the parameters of the ΛCDM model, and the experimentally measured z/µ values cannot be considered as definite evidence for the expansion hypothesis. The exponential function z+1 = eh(TL) × t(d) which is characteristic of the tired light redshift mechanism, fits the data with similarly high accuracy. Hence, on the premise of low redshift data, a decision for or against either model is completely arbitrary. We expect that in the high RS range it should be possible to check more precisely whether the HD follows the linear H₀D/c or the exponential relation, an effect that is not perceptible in the z< 1 region. Unfortunately, SN1a supernovae data are accessible only to a limited range of distances. This constraints on the data motivated several attempts to obtain cosmological parameters from gamma ray bursts observations. GRBs are the most brilliant sources in the universe. Tey are acquired up to RSs of ~8 and higher, and endeavours are made to use GRB data to calculate HD. In this study a total of 138 calibrated, cosmology independent GRB z/μ data points collected by Liu and Wei from the 557 Union2 compilations were used as the starting data set. It is shown that the Hubble diagram for high redshift gamma ray bursts shows poor agreement with the ΛCDM model, but concurs with the exponential energy decay following from the tired light redshift hypothesis.