Title: The one-loop matter bispectrum in the Effective Field Theory of Large Scale Structures

Abstract

With this study, given the importance of future large scale structure surveys for delivering new cosmological information, it is crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbative scheme to compute the clustering of dark matter in the weakly nonlinear regime in an expansion in k/k_NL, where k is the wavenumber of interest and k_NL is the wavenumber associated to the nonlinear scale. It has been recently shown that the EFTofLSS matches to 1% level the dark matter power spectrum at redshift zero up to k ≃ 0.3 h Mpc^–1 and k ≃ 0.6 h Mpc^–1 at one and two loops respectively, using only one counterterm that is fit to data. Similar results have been obtained for the momentum power spectrum at one loop. This is a remarkable improvement with respect to former analytical techniques. Here we study the prediction for the equal-time dark matter bispectrum at one loop. We find that at this order it is sufficient to consider the same counterterm that was measured in the power spectrum. Without any remaining free parameter, and in a cosmology for which kNL is smaller than in the previously consideredmore » cases (σ₈=0.9), we find that the prediction from the EFTofLSS agrees very well with N-body simulations up to k ≃ 0.25 h Mpc^–1, given the accuracy of the measurements, which is of order a few percent at the highest k's of interest. While the fit is very good on average up to k ≃ 0.25 h Mpc^–1, the fit performs slightly worse on equilateral configurations, in agreement with expectations that for a given maximum k, equilateral triangles are the most nonlinear.« less

Authors:

Angulo, Raul E. ^[1]; Foreman, Simon ^[2]; Schmittfull, Marcel ^[3]; Senatore, Leonardo ^[2]

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+ Show Author Affiliations

1. Centro de Estudios de Fisica del Cosmos de Aragon, Teruel (Spain)
2. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
3. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Publication Date:

Wed Oct 14 00:00:00 EDT 2015

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1270632

Report Number(s):

SLAC-PUB-16653
Journal ID: ISSN 1475-7516; arXiv:1406.4143

Grant/Contract Number:  

AC02-76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Cosmology and Astroparticle Physics

Additional Journal Information:

Journal Volume: 2015; Journal Issue: 10; Journal ID: ISSN 1475-7516

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; astrophysics; gravitation and cosmology; phenomenology-HEP; theory-HEP; ASTRO; cosmological perturbation theory; power spectrum; cosmic web; cosmological parameters from LSS