Cosmological and astrophysical results exploiting magnification bias with high-z sub-millimetre galaxies

TL;DR

This paper demonstrates how high-redshift submillimeter galaxies can be used as background sources in gravitational lensing studies to measure magnification bias, providing new insights into cosmological parameters and dark energy evolution.

Contribution

It introduces a tomographic analysis using SMGs as background sources to constrain cosmological models and dark energy evolution, enhancing the use of magnification bias in cosmology.

Findings

Improved constraints on cosmological parameters using magnification bias.

Evidence for the potential evolution of dark energy density.

Validation of SMGs as effective background sources for lensing studies.

Abstract

The high-z submillimeter galaxies (SMGs) can be used as background sample for gravitational lensing studies thanks to their magnification bias, which can manifest itself through a non-negligible measurement of the cross-correlation function between a background and a foreground source sample with non-overlapping redshift distributions. In particular, the choice of SMGs as background sample enhances the cross-correlation signal so as to provide an alternative and independent observable for cosmological studies regarding the probing of mass distribution. In particular the magnification bias can be exploited in order to constrain the free astrophysical parameters of a Halo Occupation Distribution model and some of the main cosmological parameters. Urged by the improvements obtained when adopting a pseudo-tomographic analysis, It has been adopted a tomographic set-up to explore not only a $\Lambda$CDM scenario, but also the possible time evolution of the dark energy density in the $\omega_0$CDM and $\omega_0\omega_a$CDM frameworks.