Daniel BaumannFerraro, SimoneSimoneFerraroGreen, DanielDanielGreenSmith, Kendrick M.Kendrick M.Smith2024-02-022024-02-022013-05-011475-7516https://scholars.lib.ntu.edu.tw/handle/123456789/639578In this article, we show that a stochastic form of scale-dependent halo bias arises in multi-source inflationary models, where multiple fields determine the initial curvature perturbation. We derive this effect for general non-Gaussian initial conditions and study various examples, such as curvaton models and quasi-single field inflation. We present a general formula for both the stochastic and the non-stochastic parts of the halo bias, in terms of the N-point cumulants of the curvature perturbation at the end of inflation. At lowest order, the stochasticity arises if the collapsed limit of the four-point function is boosted relative to the square of the three-point function in the squeezed limit. We derive all our results in two ways, using the barrier crossing formalism and the peak-background split method. In a companion paper [1], we prove that these two approaches are mathematically equivalent. © 2013 IOP Publishing Ltd and Sissa Medialab srl.cosmological perturbation theory | galaxy clustering | ination | power spectrum[SDGs]SDG8journal article10.1088/1475-7516/2013/05/0012-s2.0-84877949045https://api.elsevier.com/content/abstract/scopus_id/84877949045