Analytic halo approach to the bispectrum of galaxies in redshift space

Abstract

We present an analytic formula for the galaxy bispectrum in redshift space on the basis of the halo approach description with the halo occupation distribution of central galaxies and satellite galaxies. This work is an extension of a previous work on the galaxy power spectrum, which illuminated the significant contribution of satellite galaxies to the higher multipole spectrum through the non-linear redshift space distortions of their random motions. Behaviors of the multipoles of the bispectrum are compared with results of numerical simulations assuming a halo occupation distribution of the LOWZ sample of the SDSS-III BOSS survey. Also presented are analytic approximate formulas for the multipoles of the bispectrum, which is useful to understanding their characteristic properties. We demonstrate that the Fingers of God effect is quite important for the higher multipoles of the bispectrum in redshift space, depending on the halo occupation distribution parameters.

Galaxy bispectrum from massive spinning particles

“…Following Ref. [79], we define the vectors k 1 , k 2 , and the line-of-sight direction n, in terms of these 5 variables as…”

“…On large scales, the coherent infall velocities of galaxies into high-density regions enhance the clustering amplitudes, while on small scales, within virialized objects, the randomness of galaxy velocities causes de-phasing and leads to a suppression of clustering. The former can be calculated perturbatively, while the latter is a non-perturbative effect (see [42,79,81,96,97] for a non-exhaustive list of previous works on modeling the redshift-space galaxy bispectrum based on fitting formulae or analytical treatments using perturbation theory or halo model).…”

Grid-based calculations of redshift-space matter fluctuations from perturbation theory: UV sensitivity and convergence at the field level

“…Note that the bispectrum multipoles B (S) defined above differ from those used in the literature (e.g., Refs. [62][63][64][65], see also Ref. [66] for a comparison between different coordinate choices), but a nice property of this definition is that they are symmetric under the permutation of the order of k 1 , k 2 and k 3 .…”

Relativistic wide-angle galaxy bispectrum on the light cone

“…(89)(90)(91)(92)(93)(94), , (143)(144)(145), (152-165), (176-182), (184-185), (188), (201-226), (246), (249), (F13-F14) and (F16). ]…”

“…In particular, the bispectrum can offer a direct handle on galaxy bias [56,59,66,[77][78][79][80] and on primordial non-Gaussianity [57-59, 61, 64, 65, 81-84], as well as helping to break other degeneracies among cosmological parameters [85]. The expression of the bispectrum at tree level using the Newtonian approximation has been known for a while (see for example [86]) and subsequent improvements have been developed by [87][88][89][90][91][92][93][94], always within the Newtonian framework (see also [95][96][97]). …”