arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1808.02002astro-ph.CO
收藏

A rigorous EFT-based forward model for large-scale structure

Fabian Schmidt, Franz Elsner, Jens Jasche, Nhat Minh Nguyen, Guilhem Lavaux

英文摘要:

Conventional approaches to cosmology inference from galaxy redshift surveys are based on n-point functions, which are under rigorous perturbative control on sufficiently large scales. Here, we present an alternative approach, which employs a likelihood at the level of the galaxy density field. By integrating out small-scale modes based on effective-field theory arguments, we prove that this likelihood is under perturbative control if certain specific conditions are met. We further show that the information captured by this likelihood is equivalent to the combination of the next-to-leading order galaxy power spectrum, leading-order bispectrum, and BAO reconstruction. Combined with MCMC sampling and MAP optimization techniques, our results allow for fully Bayesian cosmology inference from large-scale structure that is under perturbative control. We illustrate this via a first demonstration of unbiased cosmology inference from nonlinear large-scale structure using this likelihood. In particular, we show unbiased estimates of the power spectrum normalization $σ_{8}$ from a catalog of simulated dark matter halos, where nonlinear information is crucial in breaking the $b_{1} - σ_{8}$ degeneracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑