Investigating dark energy by electromagnetic frequency shifts II: the Pantheon+ sample

TL;DR

This paper tests a hypothesis that observed red shifts in supernova data may include an additional frequency shift from Extended Theories of Electromagnetism, using the Pantheon+ sample to analyze potential deviations from standard cosmological models.

Contribution

It introduces a novel analysis of supernova redshift data considering an extra frequency shift component from Extended Theories of Electromagnetism, comparing results with previous Pantheon data.

Findings

Differences in the distribution of the shift parameter $z_S$ with new data

Constraints on the magnitude of the additional frequency shift

Discussion on integrating Extended Theories of Gravity into the analysis

Abstract

Following results presented in Spallicci et al. (Eur Phys J Plus 137, 2022) by the same authors, we investigate the observed red shift $z$, working under the hypothesis that it might be composed by the expansion red shift $z_{\rm C}$ and an additional frequency shift $z_{\rm S}$, towards the red or the blue, due to Extended Theories of Electromagnetism (ETE). We have tested this prediction considering the novel Pantheon+ Catalogue, composed by 1701 light curves collected by 1550 SNe Ia, and 16 BAO data, for different cosmological models characterised by the absence of a dark energy component. In particular, we shall derive which values of $z_{\rm S}$ match the observations, comparing the new results with the ones obtained considering the older Pantheon Catalogue. We find interesting differences in the resulting $z_{\rm S}$ distributions, highlighted in the text. Later, we also add a discussion regarding Extended Theories of Gravity and how to incorporate them in our methodology.