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

Bartolomeo Fiorini, Kazuya Koyama, Tessa Baker

Research output: Contribution to journalArticlepeer-review


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:
Original languageEnglish
Article number045
Number of pages26
JournalJournal of Cosmology and Astroparticle Physics
Issue number12
Publication statusPublished - 22 Dec 2023


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

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