Abstract
Our knowledge about galaxy evolution comes from transforming observed galaxy properties at different redshifts to comoving physical scales. This transformation depends on using a cosmological model.
Here, the effects of unintentional mixing of two different cosmological models on the size evolution of galaxies is studied. As a gedanken experiment, a galaxy of fixed proper size and luminosity is moved across different redshifts.
The apparent size of this galaxy is then interpreted with a cosmological model presumed by the observer, which is different compared to the cosmology exhibited by the Universe. in such a case, a spurious size evolution of the galaxy is observed. A galaxy behaving according to the R-h = ct and Neumann's cosmology, when interpreted with the Lambda cold dark matter (Lambda CDM) cosmological model, shows an increase in size by a factor of 1.1 and 1,3 from z = 7.5 to approximate to 0, respectively.
The apparent size of a galaxy in a static Euclidean cosmology, when interpreted in the Lambda CDM model, shows a factor of 23,8 increase in size between z = 7.5 to approximate to 0. This is ill close agreement with the observational data with a size increase of a factor of 6.8 between z = 3.2 to approximate to 0, Furthermore, using the apparent size data, it is shown that the difference between the derived proper sizes in R-h = ct, Neumann's and Lambda CDM cosmological models are minimal.