Euclid preparation: II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum

Euclid Collaboration, Mischa Knabenhans, Joachim Stadel, Stefano Marelli, Doug Potter, Romain Teyssier, Laurent Legrand, Aurel Schneider, Bruno Sudret, Linda Blot, Saeeda Awan, Carlo Burigana, Carla Sofia Carvalho, Hannu Kurki-Suonio, Gabriele Sirri

Research output: Contribution to journalArticleScientificpeer-review

Abstract

We present a new power spectrum emulator named EuclidEmulator that estimates the nonlinear correction to the linear dark matter power spectrum depending on the six cosmological parameters ωb, ωm, ns, h, w0, and σ8. It is constructed using the uncertainty quantification software UQLab using a spectral decomposition method called polynomial chaos expansion. All steps in its construction have been tested and optimized: the large highresolution N-body simulations carried out with PKDGRAV3 were validated using a simulation from the Euclid Flagship campaign and demonstrated to have converged up to wavenumbers k ≈ 5 h Mpc−1 for redshifts z ≤ 5. The emulator is based on 100 input cosmologies simulated in boxes of (1250 Mpc/h)3 using 20483 particles. We show that by creating mock emulators it is possible to successfully predict and optimize the performance of the final emulator prior to performing any N-body simulations. The absolute accuracy of the final nonlinear power spectrum is as good as one obtained with N-body simulations, conservatively, ∼1 per cent for k 1 h Mpc−1 and z 1. This enables efficient forward modelling in the nonlinear regime, allowing for estimation of cosmological parameters using Markov ChainMonteCarlo methods. EuclidEmulator has been compared to HALOFIT, CosmicEmu, and NGenHalofit, and shown to be more accurate than these other approaches. This work paves a new way for optimal construction of future emulators that also consider other cosmological observables, use higher resolution input simulations, and investigate higher dimensional cosmological parameter spaces.
Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society
Volume484
Issue number4
Pages (from-to)5509-5529
Number of pages21
ISSN0035-8711
DOIs
Publication statusPublished - Apr 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • methods: numerical
  • methods: statistical
  • cosmological parameters
  • large-scale structure of Universe
  • BARYON PHYSICS
  • SIMULATIONS
  • STATISTICS
  • 115 Astronomy, Space science
  • 114 Physical sciences

Cite this

Euclid Collaboration ; Knabenhans, Mischa ; Stadel, Joachim ; Marelli, Stefano ; Potter, Doug ; Teyssier, Romain ; Legrand, Laurent ; Schneider, Aurel ; Sudret, Bruno ; Blot, Linda ; Awan, Saeeda ; Burigana, Carlo ; Carvalho, Carla Sofia ; Kurki-Suonio, Hannu ; Sirri, Gabriele. / Euclid preparation : II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum. In: Monthly Notices of the Royal Astronomical Society. 2019 ; Vol. 484, No. 4. pp. 5509-5529.
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title = "Euclid preparation: II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum",
abstract = "We present a new power spectrum emulator named EuclidEmulator that estimates the nonlinear correction to the linear dark matter power spectrum depending on the six cosmological parameters ωb, ωm, ns, h, w0, and σ8. It is constructed using the uncertainty quantification software UQLab using a spectral decomposition method called polynomial chaos expansion. All steps in its construction have been tested and optimized: the large highresolution N-body simulations carried out with PKDGRAV3 were validated using a simulation from the Euclid Flagship campaign and demonstrated to have converged up to wavenumbers k ≈ 5 h Mpc−1 for redshifts z ≤ 5. The emulator is based on 100 input cosmologies simulated in boxes of (1250 Mpc/h)3 using 20483 particles. We show that by creating mock emulators it is possible to successfully predict and optimize the performance of the final emulator prior to performing any N-body simulations. The absolute accuracy of the final nonlinear power spectrum is as good as one obtained with N-body simulations, conservatively, ∼1 per cent for k 1 h Mpc−1 and z 1. This enables efficient forward modelling in the nonlinear regime, allowing for estimation of cosmological parameters using Markov ChainMonteCarlo methods. EuclidEmulator has been compared to HALOFIT, CosmicEmu, and NGenHalofit, and shown to be more accurate than these other approaches. This work paves a new way for optimal construction of future emulators that also consider other cosmological observables, use higher resolution input simulations, and investigate higher dimensional cosmological parameter spaces.",
keywords = "methods: numerical, methods: statistical, cosmological parameters, large-scale structure of Universe, BARYON PHYSICS, SIMULATIONS, STATISTICS, 115 Astronomy, Space science, 114 Physical sciences",
author = "{Euclid Collaboration} and Mischa Knabenhans and Joachim Stadel and Stefano Marelli and Doug Potter and Romain Teyssier and Laurent Legrand and Aurel Schneider and Bruno Sudret and Linda Blot and Saeeda Awan and Carlo Burigana and Carvalho, {Carla Sofia} and Hannu Kurki-Suonio and Gabriele Sirri",
year = "2019",
month = "4",
doi = "10.1093/mnras/stz197",
language = "English",
volume = "484",
pages = "5509--5529",
journal = "Monthly Notices of the Royal Astronomical Society",
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Euclid Collaboration, Knabenhans, M, Stadel, J, Marelli, S, Potter, D, Teyssier, R, Legrand, L, Schneider, A, Sudret, B, Blot, L, Awan, S, Burigana, C, Carvalho, CS, Kurki-Suonio, H & Sirri, G 2019, 'Euclid preparation: II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum' Monthly Notices of the Royal Astronomical Society, vol. 484, no. 4, pp. 5509-5529. https://doi.org/10.1093/mnras/stz197

Euclid preparation : II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum. / Euclid Collaboration; Knabenhans, Mischa; Stadel, Joachim; Marelli, Stefano; Potter, Doug; Teyssier, Romain; Legrand, Laurent; Schneider, Aurel; Sudret, Bruno; Blot, Linda; Awan, Saeeda; Burigana, Carlo; Carvalho, Carla Sofia; Kurki-Suonio, Hannu; Sirri, Gabriele.

In: Monthly Notices of the Royal Astronomical Society, Vol. 484, No. 4, 04.2019, p. 5509-5529.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Euclid preparation

T2 - II. The EUCLIDEMULATOR - a tool to compute the cosmology dependence of the nonlinear matter power spectrum

AU - Euclid Collaboration

AU - Knabenhans, Mischa

AU - Stadel, Joachim

AU - Marelli, Stefano

AU - Potter, Doug

AU - Teyssier, Romain

AU - Legrand, Laurent

AU - Schneider, Aurel

AU - Sudret, Bruno

AU - Blot, Linda

AU - Awan, Saeeda

AU - Burigana, Carlo

AU - Carvalho, Carla Sofia

AU - Kurki-Suonio, Hannu

AU - Sirri, Gabriele

PY - 2019/4

Y1 - 2019/4

N2 - We present a new power spectrum emulator named EuclidEmulator that estimates the nonlinear correction to the linear dark matter power spectrum depending on the six cosmological parameters ωb, ωm, ns, h, w0, and σ8. It is constructed using the uncertainty quantification software UQLab using a spectral decomposition method called polynomial chaos expansion. All steps in its construction have been tested and optimized: the large highresolution N-body simulations carried out with PKDGRAV3 were validated using a simulation from the Euclid Flagship campaign and demonstrated to have converged up to wavenumbers k ≈ 5 h Mpc−1 for redshifts z ≤ 5. The emulator is based on 100 input cosmologies simulated in boxes of (1250 Mpc/h)3 using 20483 particles. We show that by creating mock emulators it is possible to successfully predict and optimize the performance of the final emulator prior to performing any N-body simulations. The absolute accuracy of the final nonlinear power spectrum is as good as one obtained with N-body simulations, conservatively, ∼1 per cent for k 1 h Mpc−1 and z 1. This enables efficient forward modelling in the nonlinear regime, allowing for estimation of cosmological parameters using Markov ChainMonteCarlo methods. EuclidEmulator has been compared to HALOFIT, CosmicEmu, and NGenHalofit, and shown to be more accurate than these other approaches. This work paves a new way for optimal construction of future emulators that also consider other cosmological observables, use higher resolution input simulations, and investigate higher dimensional cosmological parameter spaces.

AB - We present a new power spectrum emulator named EuclidEmulator that estimates the nonlinear correction to the linear dark matter power spectrum depending on the six cosmological parameters ωb, ωm, ns, h, w0, and σ8. It is constructed using the uncertainty quantification software UQLab using a spectral decomposition method called polynomial chaos expansion. All steps in its construction have been tested and optimized: the large highresolution N-body simulations carried out with PKDGRAV3 were validated using a simulation from the Euclid Flagship campaign and demonstrated to have converged up to wavenumbers k ≈ 5 h Mpc−1 for redshifts z ≤ 5. The emulator is based on 100 input cosmologies simulated in boxes of (1250 Mpc/h)3 using 20483 particles. We show that by creating mock emulators it is possible to successfully predict and optimize the performance of the final emulator prior to performing any N-body simulations. The absolute accuracy of the final nonlinear power spectrum is as good as one obtained with N-body simulations, conservatively, ∼1 per cent for k 1 h Mpc−1 and z 1. This enables efficient forward modelling in the nonlinear regime, allowing for estimation of cosmological parameters using Markov ChainMonteCarlo methods. EuclidEmulator has been compared to HALOFIT, CosmicEmu, and NGenHalofit, and shown to be more accurate than these other approaches. This work paves a new way for optimal construction of future emulators that also consider other cosmological observables, use higher resolution input simulations, and investigate higher dimensional cosmological parameter spaces.

KW - methods: numerical

KW - methods: statistical

KW - cosmological parameters

KW - large-scale structure of Universe

KW - BARYON PHYSICS

KW - SIMULATIONS

KW - STATISTICS

KW - 115 Astronomy, Space science

KW - 114 Physical sciences

U2 - 10.1093/mnras/stz197

DO - 10.1093/mnras/stz197

M3 - Article

VL - 484

SP - 5509

EP - 5529

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -