Galaxy bias and halo-occupation numbers from large-scale clustering

Emiliano Sefusatti, Román Scoccimarro

    Research output: Contribution to journalArticlepeer-review


    We show that current surveys have at least as much signal to noise in higher-order statistics as in the power spectrum at weakly nonlinear scales. We discuss how one can use this information to determine the mean of the galaxy halo-occupation distribution (HOD) using only large-scale information, through galaxy bias parameters determined from the galaxy bispectrum and trispectrum. After introducing an averaged, reasonably fast to evaluate, trispectrum estimator, we show that the expected errors on linear and quadratic bias parameters can be reduced by at least 20%-40%. Also, the inclusion of the trispectrum information, which is sensitive to "three-dimensionality" of structures, helps significantly in constraining the mass dependence of the HOD mean. Our approach depends only on adequate modeling of the abundance and large-scale clustering of halos and thus is independent of details of how galaxies are distributed within halos. This provides a consistency check on the traditional approach of using two-point statistics down to small scales, which necessarily makes more assumptions. We present a detailed forecast of how well our approach can be carried out in the case of the Sloan Digital Sky Survey (SDSS).

    Original languageEnglish (US)
    Article number063001
    Pages (from-to)1-13
    Number of pages13
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Issue number6
    StatePublished - Mar 15 2005

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics
    • Physics and Astronomy (miscellaneous)


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