September, 2022. arXiv:2209.01666 [astro-ph]

Paper doi abstract bibtex

Paper doi abstract bibtex

We introduce ${\}texttt\{Hi-COLA\}$, a code designed to run fast, approximate ${\}textit\{N\}$-body simulations of non-linear structure formation in reduced Horndeski gravity. Given an input Lagrangian, ${\}texttt\{Hi-COLA\}$ dynamically constructs the appropriate field equations and consistently solves for the cosmological background, linear growth, and screened fifth force of that theory. Hence ${\}texttt\{Hi-COLA\}$ is a general, adaptable, and useful tool that allows the mildly non-linear regime of many Horndeski theories to be investigated for the first time, at low computational cost. In this work, we first describe the screening approximations and simulation setup of ${\}texttt\{Hi-COLA\}$ for theories with Vainshtein screening. We validate the code against traditional ${\}textit\{N\}$-body simulations for cubic Galileon gravity, finding $2.5{\}%$ agreement up to $k_\{{\}rm max\}=1.2{~}h/\{{\}rm Mpc\}$. To demonstrate the flexibility of ${\}texttt\{Hi-COLA\}$, we additionally run the first simulations of an extended shift-symmetric gravity theory. We use the consistency and modularity of ${\}texttt\{Hi-COLA\}$ to dissect how the modified background, linear growth, and screened fifth force all contribute to departures from ${\}Lambda$CDM in the non-linear matter power spectrum.

@misc{wright_texttthi-cola_2022, title = {\${\textbackslash}texttt\{{Hi}-{COLA}\}\$: {Fast}, approximate simulations of structure formation in {Horndeski} gravity}, shorttitle = {\${\textbackslash}texttt\{{Hi}-{COLA}\}\$}, url = {http://arxiv.org/abs/2209.01666}, doi = {10.48550/arXiv.2209.01666}, abstract = {We introduce \${\textbackslash}texttt\{Hi-COLA\}\$, a code designed to run fast, approximate \${\textbackslash}textit\{N\}\$-body simulations of non-linear structure formation in reduced Horndeski gravity. Given an input Lagrangian, \${\textbackslash}texttt\{Hi-COLA\}\$ dynamically constructs the appropriate field equations and consistently solves for the cosmological background, linear growth, and screened fifth force of that theory. Hence \${\textbackslash}texttt\{Hi-COLA\}\$ is a general, adaptable, and useful tool that allows the mildly non-linear regime of many Horndeski theories to be investigated for the first time, at low computational cost. In this work, we first describe the screening approximations and simulation setup of \${\textbackslash}texttt\{Hi-COLA\}\$ for theories with Vainshtein screening. We validate the code against traditional \${\textbackslash}textit\{N\}\$-body simulations for cubic Galileon gravity, finding \$2.5{\textbackslash}\%\$ agreement up to \$k\_\{{\textbackslash}rm max\}=1.2{\textasciitilde}h/\{{\textbackslash}rm Mpc\}\$. To demonstrate the flexibility of \${\textbackslash}texttt\{Hi-COLA\}\$, we additionally run the first simulations of an extended shift-symmetric gravity theory. We use the consistency and modularity of \${\textbackslash}texttt\{Hi-COLA\}\$ to dissect how the modified background, linear growth, and screened fifth force all contribute to departures from \${\textbackslash}Lambda\$CDM in the non-linear matter power spectrum.}, urldate = {2022-09-13}, publisher = {arXiv}, author = {Wright, Bill S. and Gupta, Ashim Sen and Baker, Tessa and Valogiannis, Georgios}, month = sep, year = {2022}, note = {arXiv:2209.01666 [astro-ph]}, keywords = {astrophysics, mentions sympy}, }

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