Diving into precision cosmology and the role of cosmic magnification

Author: Jose Luis Bernal

 

Abstract: Cosmology has officially confirmed itself as a precision science. However, there are still some tensions among different experiments and, now that the statistical uncertainties are expected to be as small as systematics errors, further research is needed to confirm and test the Standard Cosmological Model. In addition, new cosmological probes have to be used in order to break persistent degeneracies in key cosmological parameters. 

There is where cosmic magnification enters. Gravitational lensing has two effects in the image we receive from galaxies: it curves the light altering the shape of the galaxy (cosmic shear) and also magnifies it. As they are originated by the same physical phenomenon, they are sensitive to the same density field, but they depend differently on the cosmological parameters. Moreover, as the methodology is completely different, they do not share systematic errors. Hence, opening this way to probe cosmology can mean an important advance and a keystone for the future research on cosmology.