| Abstract: |
The Baryon Acoustic Oscillation (BAO) signature imprinted in the Cosmic Microwave Background (CMB) and in the three dimensional matter distribution at later cosmic times defines a characteristic scale, which is by now commonly used as a standard ruler to determine the expansion of the Universe. Many upcoming surveys are focused on measuring this signal with great accuracy. BAO reconstruction helps to linearise the density peaks traced by Luminous Red Galaxies, transferring information from the higher order statistics to the two point correlation function, which directly measures the BAO peak. However there is more information encoded in the higher orders, which can be used to estimate the clustering in the underdone regions traced by cosmic voids. We have developed the methodology to measure the BAOs from cosmic voids derived from the 3D distribution of galaxies and the way to combine that with BAO reconstruction to get tighter constraints on the BAO peak position. We warn however on doing RSD analysis with cosmic voids, as they represent a nonlinear transformation of the galaxy field in redshift space, and thus have biased peculiar motions. |
