A null test to probe the scale-invariance of the growth of structure

One specific property of the LCDM model is that the way structures are growing as a function of time is scale-independent. In this talk, I will show how to construct a null test to probe this property in a model-independent way. For this, I will combine different observables, namely the quadrupole and hexadecapole of the galaxy number counts, and the Doppler magnification dipole. This last observable is obtained by cross-correlating galaxy number counts with the cosmic convergence. I will show that deviations in the scale-independence of a few percents can be detected with a survey like SKA.