Basis function expansions of the two-point correlation function and reconstruction of the cosmological distance scale
Year: 2026
Type: preprint
Abstract: The shape of the correlation function of galaxy pairs can be used as a cosmological distance indicator. Most estimators of this shape require that one bin the pair counts, and considerable effort is expended in finding the optimal bin size. Cosmological constraints are then derived, in a separate step, by fitting to the binned pair counts. By projecting the pair counts on a suitable basis set, it is possible to estimate the pair correlation function without binning. Recent work suggests that, in the context of estimating the cosmological distance scale from galaxy clustering data, polynomials and half-integer generalized Laguerre functions are particularly useful bases. We show how to use these bases to measure the correlation function and estimate the reconstructed distance scale in a single step. Our analysis includes the effects of shot-noise and cosmic variance, and highlights the benefits of projecting pair counts onto orthogonal basis functions.
Source: arXiv (Cornell University)
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Yale University, Ministerio de Ciencia, Innovación y Universidades, Deutsche Forschungsgemeinschaft, Abdus Salam International Centre for Theoretical Physics, Munich Institute for Astro- and Particle Physics, European Regional Development Fund, Agencia Estatal de Investigación
Awards: G1105844351, Graduate Research Fellowship Program(GRFP), G4066435496, G410571670, EXC 2094: ORIGINS: Vom Ursprung des Universums bis zu den ersten Bausteinen des Lebens, G451917667, G4606110427, G491712853, G5539308778, G5635532810, G5967599077, G717256432, G7805626310, G7863371703, G8497050386
OpenAlex ID: W7214101916
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