On the number of galaxies at high redshift

TL;DR

This paper investigates the distribution of high-redshift galaxies using both standard and non-standard cosmological models, applying a new luminosity function and comparing model predictions with observational data.

Contribution

It introduces a new luminosity function based on the truncated beta distribution and compares standard and non-standard cosmological models using multiple observational tests.

Findings

Minimal differences between standard and non-standard models in the tests

The new luminosity function effectively models galaxy luminosity distributions

Observational data up to redshift 4 are consistent with both models

Abstract

The number of galaxies at a given flux as a function of the redshift, $z$, is derived when the $z$-distance relation is non-standard. In order to compare different models, the same formalism is also applied to the standard cosmology. The observed luminosity function for galaxies of the zCOSMOS catalog at different redshifts is modelled by a new luminosity function for galaxies, which is derived by the truncated beta probability density function. Three astronomical tests, which are the photometric maximum as a function of the redshift for a fixed flux, the mean value of the redshift for a fixed flux, and the luminosity function for galaxies as a function of the redshift, compare the theoretical values of the standard and non-standard model with the observed value. The tests are performed on the FORS Deep Field (FDF) catalog up to redshift $z=1.5$ and on the zCOSMOS catalog extending beyond $z=4$. These three tests show minimal differences between the standard and the non-standard models.