Mitigating baryon feedback bias in cosmic shear through a theoretical error covariance in the matter power spectrum
arXiv:2410.12500 · doi:10.1093/mnras/staf113
Abstract
Forthcoming cosmic shear surveys will make precise measurements of the matter density field down to very small scales, scales which are dominated by baryon feedback. The modelling of baryon feedback is crucial to ensure unbiased cosmological parameter constraints; the most efficient approach is to use analytic models, but these are limited by how well they can capture the physics of baryon feedback. We investigate the fitting and residual errors of various baryon feedback models to a suite of hydrodynamic simulations, and propagate these to cosmological parameter constraints for cosmic shear. We present an alternative formalism to binary scale-cuts through the use of a theoretical error covariance, which is a well-motivated alternative using errors in the power spectrum modelling itself. We depart from previous works by modelling baryonic feedback errors directly in the matter power spectrum, which is the natural basis to do so and thus preserves information in the lensing kernels. When including angular multipoles up to , and assuming Euclid-like survey properties, we find that even multi-parameter models of baryon feedback can introduce significant levels of bias. In contrast, our theoretical error reduces the bias in and to acceptable levels, with only a modest increase in parameter variances. The theoretical error approach bypasses the need to directly determine the per-bin values, as it naturally suppresses the biassing small-scale information. We also present a detailed study of how flexible HMCode-2020, a widely-used non-linear and baryonic feedback model, is at fitting a range of hydrodynamical simulations.
15 pages, 16 figures, submitted to MNRAS
References in corpus (53)
- The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
- Weak Gravitational Lensing
- Stable clustering, the halo model and nonlinear cosmological power spectra
- Halo Models of Large Scale Structure
- First results from the IllustrisTNG simulations: matter and galaxy clustering
- Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
- Revising the Halofit Model for the Nonlinear Matter Power Spectrum
- Analytic model for galaxy and dark matter clustering
- Simba: Cosmological Simulations with Black Hole Growth and Feedback
- Halo occupation numbers and galaxy bias
- KiDS-1000 Cosmology: Cosmic shear constraints and comparison between two point statistics
- KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
- Cosmology with cosmic shear observations: a review
- The Illustris Simulation: Public Data Release
- PolyChord: nested sampling for cosmology
- The BAHAMAS project: Calibrated hydrodynamical simulations for large-scale structure cosmology
- PolyChord: next-generation nested sampling
- The effects of galaxy formation on the matter power spectrum: A challenge for precision cosmology
- Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Data Calibration
- Gravitational Lensing
- An accurate halo model for fitting non-linear cosmological power spectra and baryonic feedback models
- Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Modeling Uncertainty
- HMcode-2020: Improved modelling of non-linear cosmological power spectra with baryonic feedback
- Quantifying the effect of baryon physics on weak lensing tomography
- CosmoSIS: modular cosmological parameter estimation
- Accurate halo-model matter power spectra with dark energy, massive neutrinos and modified gravitational forces
- Hyper Suprime-Cam Year 3 Results: Cosmology from Cosmic Shear Power Spectra
- A new method to quantify the effects of baryons on the matter power spectrum
- Quantifying baryon effects on the matter power spectrum and the weak lensing shear correlation
- The impact of baryons on the matter power spectrum from the Horizon-AGN cosmological hydrodynamical simulation
- Modelling baryonic feedback for survey cosmology
- Exploring the effects of galaxy formation on matter clustering through a library of simulation power spectra
- Matter power spectrum and the challenge of percent accuracy
- DES Y3 + KiDS-1000: Consistent cosmology combining cosmic shear surveys
- Hydrodynamical simulations of the galaxy population: enduring successes and outstanding challenges
- Measuring neutrino masses with large-scale structure: Euclid forecast with controlled theoretical error
- Modeling baryonic physics in future weak lensing surveys
- Analytic model for the matter power spectrum, its covariance matrix, and baryonic effects
- Cosmology in the era of Euclid and the Square Kilometre Array
- Emulation of baryonic effects on the matter power spectrum and constraints from galaxy cluster data
- Joint constraints on cosmology and the impact of baryon feedback: combining KiDS-1000 lensing with the thermal Sunyaev-Zeldovich effect from Planck and ACT
- Dark Energy Survey Year 3 results: cosmological constraints from the analysis of cosmic shear in harmonic space
- SP(k) -- A hydrodynamical simulation-based model for the impact of baryon physics on the non-linear matter power spectrum
- KiDS-1000: Cosmology with improved cosmic shear measurements
- The Bacco Simulation Project: Bacco Hybrid Lagrangian Bias Expansion Model in Redshift Space
- DES Y1 results: Splitting growth and geometry to test CDM
- The impact of baryons on the sensitivity of dark energy measurements
- Consistency of cosmic shear analyses in harmonic and real space
- Sufficiency of a Gaussian power spectrum likelihood for accurate cosmology from upcoming weak lensing surveys
- Geometry and growth contributions to cosmic shear observables
- On Mitigation of the Uncertainty in Nonlinear Matter Clustering for Cosmic Shear Tomography
- Mitigating baryonic effects with a theoretical error covariance
- Growth and Geometry Split in Light of the DES-Y3 Survey