A control variate technique using differenced estimates from realistic masked and isotropic simulations reduces the computational cost of CMB lensing bias calculations by a factor of three to five.
CMB lensing power spectrum estimation without instrument noise bias
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
The power spectrum of cosmic microwave background (CMB) lensing will be measured to sub-percent precision with upcoming surveys, enabling tight constraints on the sum of neutrino masses and other cosmological parameters. Measuring the lensing power spectrum involves the estimation of the connected trispectrum of the four-point function of the CMB map, which requires the subtraction of a large Gaussian disconnected noise bias. This reconstruction noise bias receives contributions both from CMB and foreground fluctuations as well as instrument noise (both detector and atmospheric noise for ground-based surveys). The debiasing procedure therefore relies on the quality of simulations of the instrument noise which may be expensive or inaccurate. We propose a new estimator that makes use of at least four splits of the CMB maps with independent instrument noise. This estimator makes the CMB lensing power spectrum completely insensitive to any assumptions made in modeling or simulating the instrument noise. We show that this estimator, in many practical situations, leads to no substantial loss in signal-to-noise. We provide an efficient algorithm for its computation that scales with the number of splits $m$ as $\mathcal{O}(m^2)$ as opposed to a naive $\mathcal{O}(m^4)$ expectation.
citation-role summary
background 1
citation-polarity summary
fields
astro-ph.CO 4roles
background 1polarities
background 1representative citing papers
ACT DR6 CMB lensing map gives σ8 = 0.819 ± 0.015 and H0 = 68.3 ± 1.1 km/s/Mpc, consistent with Planck ΛCDM but 1.7-2.1σ higher in S8 than KiDS, DES, and HSC galaxy surveys.
ACT DR6 yields a 2.3% precise CMB lensing power spectrum with A_lens = 1.013 ± 0.023 relative to Planck 2018 Lambda CDM, giving S8 = 0.818 ± 0.022 and no evidence for suppressed structure growth.
First CMB lensing reconstruction from two years of SPT-3G Summer temperature data yields A_comb = 1.015 ± 0.053 over 50 < L < 2000, consistent with Planck 2018 ΛCDM.
citing papers explorer
-
Faster CMB lensing with control variates
A control variate technique using differenced estimates from realistic masked and isotropic simulations reduces the computational cost of CMB lensing bias calculations by a factor of three to five.
-
The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
ACT DR6 CMB lensing map gives σ8 = 0.819 ± 0.015 and H0 = 68.3 ± 1.1 km/s/Mpc, consistent with Planck ΛCDM but 1.7-2.1σ higher in S8 than KiDS, DES, and HSC galaxy surveys.
-
The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
ACT DR6 yields a 2.3% precise CMB lensing power spectrum with A_lens = 1.013 ± 0.023 relative to Planck 2018 Lambda CDM, giving S8 = 0.818 ± 0.022 and no evidence for suppressed structure growth.
-
CMB Lensing Reconstruction Using Two Years of Temperature Data from the SPT-3G Summer Survey
First CMB lensing reconstruction from two years of SPT-3G Summer temperature data yields A_comb = 1.015 ± 0.053 over 50 < L < 2000, consistent with Planck 2018 ΛCDM.