On the $2^\text{nd}$ feature of the matter two-point function

Abstract

We point out the existence of a second feature in the matter two-point function, besides the acoustic peak, due to the baryon-baryon correlation in the early universe and positioned at twice the distance of the peak. We discuss how the existence of this feature is implied by the well-known heuristic argument that explains the baryon bump in the correlation function. A standard $\chi^2$ analysis to estimate the detection significance of the second feature is mimicked. We conclude that for realistic values of the baryon density, an SKA-like galaxy survey will not be able to detect this feature with standard correlation function analysis.