Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- 1 The Homogeneous and Isotropic Universe
- 2 Perturbation Theory
- 3 Initial Conditions
- 4 CMB Anisotropies
- 5 CMB Polarization and the Total Angular Momentum Approach
- 6 Non-Gaussianities
- 7 Lensing and the CMB
- 8 Observations of Large-Scale Structure
- 9 Cosmological Parameter Estimation
- 10 The Frequency Spectrum of the CMB
- Appendix 1 Fundamental Constants, Units and Relations
- Appendix 2 General Relativity
- Appendix 3 Perturbations
- Appendix 4 Special Functions
- Appendix 5 Special Functions
- Appendix 6 Mixtures
- Appendix 7 Statistical Utensils
- Appendix 8 Approximation for the Tensor Cℓ Spectrum
- Appendix 9 Boltzmann Equation in a Universe with Curvature
- Appendix 10 Perturbations of the Luminosity Distance
- References
- Index
7 - Lensing and the CMB
Published online by Cambridge University Press: 10 December 2020
Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- 1 The Homogeneous and Isotropic Universe
- 2 Perturbation Theory
- 3 Initial Conditions
- 4 CMB Anisotropies
- 5 CMB Polarization and the Total Angular Momentum Approach
- 6 Non-Gaussianities
- 7 Lensing and the CMB
- 8 Observations of Large-Scale Structure
- 9 Cosmological Parameter Estimation
- 10 The Frequency Spectrum of the CMB
- Appendix 1 Fundamental Constants, Units and Relations
- Appendix 2 General Relativity
- Appendix 3 Perturbations
- Appendix 4 Special Functions
- Appendix 5 Special Functions
- Appendix 6 Mixtures
- Appendix 7 Statistical Utensils
- Appendix 8 Approximation for the Tensor Cℓ Spectrum
- Appendix 9 Boltzmann Equation in a Universe with Curvature
- Appendix 10 Perturbations of the Luminosity Distance
- References
- Index
Summary
We introduce weak lensing due to foreground structures with the aim of treating lensing of CMB anisotropies and polarization. This second-order effect is especially important on small scales but has to be taken into account for ℓ ≳ 400 if we want to achieve an accuracy of better than 1%. We first derive the deflection angle and the lensing power spectrum. Then we discuss lensing of CMB fluctuations and polarization in the at sky approximation, which is sufficiently accurate for angular harmonics with ℓ ≳50 where lensing is relevant.
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- The Cosmic Microwave Background , pp. 268 - 295Publisher: Cambridge University PressPrint publication year: 2020