Preface xi About the Companion Website xv 1 A Brief History of Cosmological Ideas 1 2 Observational Overview 3 2.1 In visible light 4 2.2 In other wavebands 8 2.3 Homogeneity and isotropy 11 2.4 The expansion of the Universe 11 2.5 Particles in the Universe 14 3 Newtonian Gravity 21 3.1 The Friedmann equation 22 3.2 On the meaning of the expansion 25 3.

3 Things that go faster than light 25 3.4 The fluid equation 26 3.5 The acceleration equation 27 3.6 On mass, energy, and vanishing factors of c2 28 4 The Geometry of the Universe 31 4.1 Flat geometry 31 4.2 Spherical geometry 32 4.3 Hyperbolic geometry 35 4.4 Infinite and observable universes 36 4.

5 Where did the Big Bang happen? 36 4.6 Three values of k 37 5 Simple Cosmological Models 39 5.1 Hubble''s law 39 5.2 Expansion and redshift 40 5.3 Solving the equations 41 5.4 Particle number densities 46 5.5 Evolution including curvature 47 6 Observational Parameters 51 6.1 The expansion rate H0 51 6.

2 The density parameter Ω0 53 6.3 The deceleration parameter q0 55 7 The Cosmological Constant 57 7.1 Introducing Λ 57 7.2 Fluid description of Λ 58 7.3 Cosmological models with Λ 60 8 The Age of the Universe 63 9 The Density of the Universe and Dark Matter 69 9.1 Weighing the Universe 69 9.2 What might the dark matter be? 76 9.3 Dark matter searches 78 10 The Cosmic Microwave Background 81 10.

1 Properties of the microwave background 81 10.2 The photon to baryon ratio 83 10.3 The origin of the microwave background 84 10.4 The origin of the microwave background (optional advanced treatment) 87 11 The Early Universe 91 12 Nucleosynthesis: The Origin of the Light Elements 99 12.1 Hydrogen and helium 100 12.2 Comparing with observations 103 12.3 Contrasting decoupling and nucleosynthesis 105 13 The Inflationary Universe 107 13.1 Problems with the Hot Big Bang 107 13.

2 Inflationary expansion 111 13.3 Solving the Big Bang problems 113 13.4 How much inflation? 115 13.5 Inflation and particle physics 116 14 The Initial Singularity 121 15 Overview: The Standard Cosmological Model 125 15.1 Expansion 126 15.2 Geometry 126 15.3 Age 126 15.4 Fate 126 15.

5 Contents 127 15.6 Early history 128 15.7 Outlook 128 Advanced Topic 1 General Relativistic Cosmology 129 A1.1 The metric of space-time 129 A1.2 The Einstein equations 131 A1.3 Aside: Topology of the Universe 132 Advanced Topic 2 Classic Cosmology: Distances and Luminosities 135 A2.1 Light propagation and redshift 135 A2.2 The observable Universe 138 A2.

3 Luminosity distance 138 A2.4 Angular diameter distance 143 A2.5 Source counts 145 Advanced Topic 3 Neutrino Cosmology 149 A3.1 The massless case 149 A3.2 Massive neutrinos 151 A3.3 Neutrinos and structure formation 153 Advanced Topic 4 Baryogenesis 157 Advanced Topic 5 Structures in the Universe 161 A5.1 The observed structures 161 A5.2 Gravitational instability 163 A5.

3 The clustering of galaxies 165 A5.4 Cosmic microwave background anisotropies 167 A5.5 The origin of structure 173 Advanced Topic 6 Constraining Cosmological Models 177 A6.1 Cosmological models and parameters 177 A6.2 Key cosmological observations 178 A6.3 Cosmological data analysis 179 A6.4 The Standard Cosmological Model: 2025 edition 181 A6.5 Tensions and hints of new physics 184 A6.

6 The future 185 Bibliography 187 Numerical Answers and Hints to Problems 191 Index 197.