Constraining the growth rate of structure with phase correlations

Joyce Byun, Felipe Oliveira Franco, Cullan Howlett, Camille Bonvin, Danail Obreschkow

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


We show that correlations between the phases of the galaxy density field in redshift space provide additional information about the growth rate of large-scale structure that is complementary to the power-spectrum multipoles. In particular, we consider the multipoles of the line correlation function (LCF), which correlates phases between three collinear points, and use the Fisher forecasting method to show that the LCF multipoles can break the degeneracy between the measurement of the growth rate of structure f and the amplitude of perturbations s8 that is present in the power-spectrum multipoles at large scales. This leads to an improvement in the measurement offand s8 by up to 220 percent for kmax = 0.15hMpc-1 and up to 50 percent for kmax = 0.30 h Mpc-1 at redshift z = 0.25, with respect to power-spectrum measurements alone for the upcoming generation of galaxy surveys like DESI and Euclid. The average improvements in the constraints on f and s8 for kmax = 0.15hMpc-1 are ~90 per cent for the DESI BGS sample with mean redshift z = 0.25, ~40 per cent for the DESI ELG sample with z = 1.25, and ~40 percent for the Euclid Ha galaxies with z = 1.3. For kmax = 0.30 hMpc-1, the average improvements are ~40 percent for the DESI BGS sample and ~20 percent for both the DESI ELG and Euclid Ha galaxies.

Original languageEnglish
Pages (from-to)1765-1790
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
Publication statusPublished - 1 Sep 2020


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