Accurate Baryon Acoustic Oscillations reconstruction via semi-discrete optimal transport

TL;DR

This paper introduces an efficient semi-discrete optimal transport method for reconstructing the linear density field in cosmology, significantly improving the accuracy of Baryon Acoustic Oscillation scale recovery.

Contribution

It presents a novel application of geometry processing techniques to optimal transport for cosmological density field reconstruction, achieving higher precision than existing methods.

Findings

Uncertainties reduced by a factor of 4.3 compared to no reconstruction.

Uncertainties reduced by a factor of 3.1 compared to standard reconstruction.

Accurate retrieval of BAO scale in noise-less simulations.

Abstract

Optimal transport theory has recently reemerged as a vastly resourceful field of mathematics with elegant applications across physics and computer science. Harnessing methods from geometry processing, we report on the efficient implementation for a specific problem in cosmology -- the reconstruction of the linear density field from low redshifts, in particular the recovery of the Baryonic Acoustic Oscillation (BAO) scale. We demonstrate our algorithm's accuracy by retrieving the BAO scale in noise-less cosmological simulations that are dedicated to cancel cosmic variance; we find uncertainties to be reduced by a factor of 4.3 compared with performing no reconstruction, and a factor of 3.1 compared with standard reconstruction.