http://arxiv.org/abs/1701.03374
Modeling the nonlinearity of the halo bispectrum remains a major challenge in modern cosmology, in particular for ongoing and upcoming large-scale structure observations that are performed to study the inflationary physics. The “power spectrum response” offers a solution for bispectrum in the so-called squeezed limit, in which one wavenumber is much smaller than the other two. As a first step, we demonstrate that the halo squeezed-limit bispectrum computed from the brute-force second-order perturbation theory agrees precisely with the responses of ${\it linear}$ halo power spectrum to large-scale density and potential fluctuations. Since the halo power spectrum responses to arbitrarily small scales can straightforwardly be obtained by separate universe simulations, the response approach provides a novel and powerful technique to model the nonlinear halo squeezed-limit bispectrum.
C. Chiang
Fri, 13 Jan 17
18/44
Comments: 7 pages
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