Fast production of cosmological emulators in modified gravity: the matter power spectrum

Bartolomeo Fiorini, Kazuya Koyama, Tessa Baker

Research output: Contribution to journalArticlepeer-review

Abstract

We test the convergence of fast simulations based on the COmoving Lagrangian Acceleration (COLA) method for predictions of the matter power spectrum, specialising our analysis in the redshift range 1 ≤ z ≤ 1.65, relevant to high-redshift spectroscopic galaxy surveys. We then focus on the enhancement of the matter power spectrum in modified gravity (MG), the boost factor, using the Dvali-Gabadadze-Porrati (DGP) theory as a test case but developing a general approach that can be applied to other MG theories. After identifying the minimal simulation requirements for accurate DGP boost factors, we design and produce a COLA simulation suite that we use to train a neural network emulator for the DGP boost factor. Using MG-AREPO simulations as a reference, we estimate the emulator accuracy to be of ∼ 3% up to k = 5 h Mpc−1 at 0 ≤ z ≤ 2. We make the emulator publicly available at: https://github.com/BartolomeoF/nDGPemu.
Original languageEnglish
Article number045
Number of pages26
JournalJournal of Cosmology and Astroparticle Physics
Volume2023
Issue number12
DOIs
Publication statusPublished - 22 Dec 2023

Keywords

  • UKRI
  • STFC
  • RF\ERE\210304
  • ST/W001225/1
  • ERC
  • StG 949572
  • URF\R1\180009

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