Self-calibration of weak lensing systematic effects using combined two- and three-point statistics
| Autor: | Benjamin Joachimi, Susan Pyne |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Equation of state (cosmology) Calibration (statistics) FOS: Physical sciences Sigma Spectral density Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Redshift Space and Planetary Science Dark energy Statistical physics Bispectrum Weak gravitational lensing Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 503:2300-2317 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab413 |
| Popis: | We investigate the prospects for using the weak lensing bispectrum alongside the power spectrum to control systematic uncertainties in a Euclid-like survey. Three systematic effects are considered: the intrinsic alignment of galaxies, uncertainties in the means of tomographic redshift distributions, and multiplicative bias in the measurement of the shear signal. We find that the bispectrum is very effective in mitigating these systematic errors. Varying all three systematics simultaneously, a joint power spectrum and bispectrum analysis reduces the area of credible regions for the cosmological parameters $\Omega_\mathrm{m}$ and $\sigma_8$ by a factor of 90 and for the two parameters of a time-varying dark energy equation of state by a factor of almost 20, compared with the baseline approach of using the power spectrum alone and of imposing priors consistent with the accuracy requirements specified for Euclid. We also demonstrate that including the bispectrum self-calibrates all three systematic effects to the stringent levels required by the forthcoming generation of weak lensing surveys, thereby reducing the need for external calibration data. Comment: Accepted for publication in MNRAS, 22 pages |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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