1. The expansion of the universe. Spacetime geometry ; The cosmological redshift ; Distances at small redshift : the Hubble constant ; Luminosity distances and angular diameter distances ; Dynamics of expansion ; Distances at large redshifts : accelerated expansion ; Cosmic expansion or tired light? ; Ages ; Masses ; Intergalactic absorption ; Number counts ; Quintessence ; Horizons --

2. The cosmic microwave radiation background. Expectations and discovery of the microwave background ; The equilibrium era ; Recombination and last scattering ; The dipole anisotropy ; The Sunyaev-Zel'dovich effect ; Primary fluctuations in the microwave background : a first look --

3. The early universe. Thermal history ; Cosmological nucleosynthesis ; Baryonsynthesis and leptonsynthesis ; Cold dark matter --

4. Inflation. Three puzzles ; Slow-roll inflation ; Chaotic inflation, eternal inflation --

5. General theory of small fluctuations. Field equations ; Fourier decomposition and stochastic initial conditions ; Choosing a gauge ; Conservation outside the horizon.

6. Evolution of cosmological fluctuations, Scalar perturbations : kinetic theory ; Scalar perturbations : the hydrodynamic limit ; Scalar perturbations : long wavelengths ; Scalar perturbations : short wavelengths ; Scalar perturbations : interpolation & transfer functions ; Tensor perturbations --

7. Anisotropies in the microwave sky. General formulas for the temperature flucations ; Temperature multipole coefficients : scalar modes ; Temperature multipole coefficients : tensor modes ; Polarization --

8. The growth of structure. Linear perturbations after recombination ; Nonlinear growth ; Collapse of baryonic matter --

9. Gravitational lenses. Lens equation for point masses ; Magnification : strong lensing and microlensing ; Extended lenses ; Time delay ; Weak lensing ; Cosmic strings --

10. Inflation as the origin of cosmological fluctuations. Scalar fluctuations during inflation ; Tensor fluctuations during inflation ; Fluctuations during inflation : the slow-roll approximation ; Multifield inflation --

Appendices. A. Some useful numbers ; B. Review of general relativity ; C. Energy transfer between radiation and electrons ; D. The Ergodic theorem ; E. Gaussian distributions ; F. Newtonian cosmology ; G. Photon polarization ; H. The relativistic Boltzmann equation --

Glossary of symbols --

Assorted problems.