Systematic errors in the measurement of neutrino masses due to baryonic feedback processes: Prospects for stage IV lensing surveys

Abstract

We examine the importance of baryonic feedback effects on the matter power spectrum on small scales, and the implications for the precise measurement of neutrino masses through gravitational weak lensing. Planned large galaxy surveys such as the Large Synoptic Sky Telescope (LSST) and Euclid are expected to measure the sum of neutrino masses to extremely high precision, sufficient to detect non-zero neutrino masses even in the minimal mass normal hierarchy. We show that weak lensing of galaxies while being a very good probe of neutrino masses, is extremely sensitive to baryonic feedback processes. We use publicly available results from the Overwhelmingly Large Simulations (OWLS) project to investigate the effects of active galactic nuclei feedback, the nature of the stellar initial mass function, and gas cooling rates, on the measured weak lensing shear power spectrum. Using the Fisher matrix formalism and priors from CMB+BAO data, we show that when one does not account for feedback, the measured neutrino mass may be substantially larger or smaller than the true mass, depending on the dominant feedback mechanism, with the mass error |Δm_nu| often exceeding the mass m_nu itself. We also consider gravitational lensing of the cosmic microwave background (CMB) and show that it is not sensitive to baryonic feedback on scales l < 2000, although CMB experiments that aim for sensitivities sigma(m_nu) < 0.02 eV will need to include baryonic effects in modeling the CMB lensing potential. A combination of CMB lensing and galaxy lensing can help break the degeneracy between neutrino masses and baryonic feedback processes. We conclude that future large galaxy lensing surveys such as LSST and Euclid can only measure neutrino masses accurately if the matter power spectrum can be measured to similar accuracy.

No major changes. References added, and text expanded. Published in Phys. Rev. D, and replaced to reflect the published version

References in corpus (6)

• Properties of galaxies reproduced by a hydrodynamic simulation
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• Effects of Baryons and Dissipation on the Matter Power Spectrum
• Detection of Gravitational Lensing in the Cosmic Microwave Background
• The Effect of Thermal Neutrino Motion on the Non-linear Cosmological Matter Power Spectrum
• Impact of massive neutrinos on nonlinear matter power spectrum

Cited by in corpus (17)

• Baryons, Neutrinos, Feedback and Weak Gravitational Lensing
• The halo model in a massive neutrino cosmology
• The Benefits of CMB Delensing
• The contributions of matter inside and outside of haloes to the matter power spectrum
• Strong detection of the CMB lensingxgalaxy weak lensingcross-correlation from ACT-DR4,PlanckLegacy and KiDS-1000
• Beware of commonly used approximations I: errors in forecasts
• Beware of commonly used approximations II: estimating systematic biases in the best-fit parameters
• Baryonic feedback biases on fundamental physics from lensed CMB power spectra
• Inference from the small scales of cosmic shear with current and future Dark Energy Survey data
• General Relativistic Corrections to the Weak Lensing Convergence Power Spectrum
• Avoiding baryonic feedback effects on neutrino mass measurements from CMB lensing
• Mitigating Foreground Bias to the CMB Lensing Power Spectrum for a CMB-HD Survey
• Science from an Ultra-Deep, High-Resolution Millimeter-Wave Survey
• Cosmological Leverage from the Matter Power Spectrum in the Presence of Baryon and Nonlinear Effects
• Baryonic effects in the Effective Field Theory of Large-Scale Structure and an analytic recipe for lensing in CMB-S4
• Cosmological Implications of a Neutrino Mass Detection
• The Kaiser-Rocket effect: three decades and counting