English

A Model for the Squeezed Bispectrum in the Non-Linear Regime

Cosmology and Nongalactic Astrophysics 2023-09-14 v2

Abstract

We present a model for the squeezed dark matter bispectrum, where the short modes are deep in the non-linear regime. We exploit the consistency relations for large-scale structures combined with a response function approach to write the squeezed bispectrum in terms of a few unknown functions of the short modes. We provide an ansatz for a fitting function for these response functions, checking that the resulting model is reliable when compared to the one-loop squeezed bispectrum. We then test the model against measured bispectra from numerical simulations for short modes ranging between k0.1h/k \sim 0.1 \, h/Mpc, and k0.7h/k \sim 0.7 \, h/Mpc at redshift z=0z=0. To evaluate the goodness of the fit of our model we implement a non-Gaussian covariance and find agreement within 11-σ\sigma standard deviation of the simulated data.

Keywords

Cite

@article{arxiv.2212.11940,
  title  = {A Model for the Squeezed Bispectrum in the Non-Linear Regime},
  author = {Matteo Biagetti and Juan Calles and Lina Castiblanco and Katherine González and Jorge Noreña},
  journal= {arXiv preprint arXiv:2212.11940},
  year   = {2023}
}

Comments

19 pages, 5 figures; v2 added references, corrected minor typos, prepared for submission to JCAP

R2 v1 2026-06-28T07:49:28.553Z