| Preface to the First Edition | xvii |
| Preface to the Second Edition | xxi |
Chapter 1. | Measure and Integration | 1 |
1.1 | Introduction | 1 |
1.2 | Basic notions of measure theory | 4 |
1.3 | Monotone class theorem | 9 |
1.4 | Uniqueness of measures | 11 |
1.5 | Definition of measurable functions and integrals | 12 |
1.6 | Monotone convergence | 17 |
1.7 | Fatou's lemma | 18 |
1.8 | Dominated convergence | 19 |
1.9 | Missing term in Fatou's lemma | 21 |
1.10 | Product measure | 23 |
1.11 | Commutativity and associativity of product measures | 24 |
1.12 | Fubini's theorem | 25 |
1.13 | Layer cake representation | 26 |
1.14 | Bathtub principle | 28 |
1.15 | Constructing a measure from an outer measure | 29 |
1.16 | Uniform convergence except on small sets | 31 |
1.17 | Simple functions and really simple functions | 32 |
1.18 | Approximation by really simple functions | 34 |
1.19 | Approximation by C[superscript infinity] functions | 36 |
| Exercises | 37 |
Chapter 2. | L[superscript p]-Spaces | 41 |
2.1 | Definition of L[superscript p]-spaces | 41 |
2.2 | Jensen's inequality | 44 |
2.3 | Holder's inequality | 45 |
2.4 | Minkowski's inequality | 47 |
2.5 | Hanner's inequality | 49 |
2.6 | Differentiability of norms | 51 |
2.7 | Completeness of L[superscript p]-spaces | 52 |
2.8 | Projection on convex sets | 53 |
2.9 | Continuous linear functionals and weak convergence | 54 |
2.10 | Linear functionals separate | 56 |
2.11 | Lower semicontinuity of norms | 57 |
2.12 | Uniform boundedness principle | 58 |
2.13 | Strongly convergent convex combinations | 60 |
2.14 | The dual of L[superscript p]([Omega]) | 61 |
2.15 | Convolution | 64 |
2.16 | Approximation by C[superscript infinity]-functions | 64 |
2.17 | Separability of L[superscript p](R[superscript n]) | 67 |
2.18 | Bounded sequences have weak limits | 68 |
2.19 | Approximation by C[superscript infinity subscript c]-functions | 69 |
2.20 | Convolution of functions in dual L[superscript p](R[superscript n])-spaces are continuous | 70 |
2.21 | Hilbert-spaces | 71 |
| Exercises | 75 |
Chapter 3. | Rearrangement Inequalities | 79 |
3.1 | Introduction | 79 |
3.2 | Definition of functions vanishing at infinity | 80 |
3.3 | Rearrangements of sets and functions | 80 |
3.4 | The simplest rearrangement inequality | 82 |
3.5 | Nonexpansivity of rearrangement | 83 |
3.6 | Riesz's rearrangement inequality in one-dimension | 84 |
3.7 | Riesz's rearrangement inequality | 87 |
3.8 | General rearrangement inequality | 93 |
3.9 | Strict rearrangement inequality | 93 |
| Exercises | 95 |
Chapter 4. | Integral Inequalities | 97 |
4.1 | Introduction | 97 |
4.2 | Young's inequality | 98 |
4.3 | Hardy-Littlewood-Sobolev inequality | 106 |
4.4 | Conformal transformations and stereographic projection | 110 |
4.5 | Conformal invariance of the Hardy-Littlewood-Sobolev inequality | 114 |
4.6 | Competing symmetries | 117 |
4.7 | Proof of Theorem 4.3: Sharp version of the Hardy-Littlewood-Sobolev inequality | 119 |
4.8 | Action of the conformal group on optimizers | 120 |
| Exercises | 121 |
Chapter 5. | The Fourier Transform | 123 |
5.1 | Definition of the L[superscript 1] Fourier transform | 123 |
5.2 | Fourier transform of a Gaussian | 125 |
5.3 | Plancherel's theorem | 126 |
5.4 | Definition of the L[superscript 2] Fourier transform | 127 |
5.5 | Inversion formula | 128 |
5.6 | The Fourier transform in L[superscript p](R[superscript n]) | 128 |
5.7 | The sharp Hausdorff-Young inequality | 129 |
5.8 | Convolutions | 130 |
5.9 | Fourier transform of |x|[superscript [alpha]-n] | 130 |
5.10 | Extension of 5.9 to L[superscript p](R[superscript n]) | 131 |
| Exercises | 133 |
Chapter 6. | Distributions | 135 |
6.1 | Introduction | 135 |
6.2 | Test functions (The space D([Omega])) | 136 |
6.3 | Definition of distributions and their convergence | 136 |
6.4 | Locally summable functions, L[superscript p subscript loc]([Omega]) | 137 |
6.5 | Functions are uniquely determined by distributions | 138 |
6.6 | Derivatives of distributions | 139 |
6.7 | Definition of W[superscript 1,p subscript loc]([Omega]) and W[superscript 1,p]([Omega]) | 140 |
6.8 | Interchanging convolutions with distributions | 142 |
6.9 | Fundamental theorem of calculus for distributions | 143 |
6.10 | Equivalence of classical and distributional derivatives | 144 |
6.11 | Distributions with zero derivatives are constants | 146 |
6.12 | Multiplication and convolution of distributions by C[superscript infinity]-functions | 146 |
6.13 | Approximation of distributions by C[superscript infinity]-functions | 147 |
6.14 | Linear dependence of distributions | 148 |
6.15 | C[superscript infinity]([Omega]) is 'dense' in W[superscript 1,p subscript loc]([Omega]) | 149 |
6.16 | Chain rule | 150 |
6.17 | Derivative of the absolute value | 152 |
6.18 | Min and Max of W[superscript 1,p]-functions are in W[superscript 1,p] | 153 |
6.19 | Gradients vanish on the inverse of small sets | 154 |
6.20 | Distributional Laplacian of Green's functions | 156 |
6.21 | Solution of Poisson's equation | 157 |
6.22 | Positive distributions are measures | 159 |
6.23 | Yukawa potential | 163 |
6.24 | The dual of W[superscript 1,p](R[superscript n]) | 166 |
| Exercises | 167 |
Chapter 7. | The Sobolev Spaces H[superscript 1] and H[superscript 1/2] | 171 |
7.1 | Introduction | 171 |
7.2 | Definition of H[superscript 1]([Omega]) | 171 |
7.3 | Completeness of H[superscript 1]([Omega]) | 172 |
7.4 | Multiplication by functions in C[superscript infinity]([Omega]) | 173 |
7.5 | Remark about H[superscript 1]([Omega]) and W[superscript 1,2]([Omega]) | 174 |
7.6 | Density of C[superscript infinity]([Omega]) in H[superscript 1]([Omega]) | 174 |
7.7 | Partial integration for functions in H[superscript 1](R[superscript n]) | 175 |
7.8 | Convexity inequality for gradients | 177 |
7.9 | Fourier characterization of H[superscript 1](R[superscript n]) | 179 |
| Heat kernel | 180 |
7.10 | -[Delta] is the infinitesimal generator of the heat kernel | 181 |
7.11 | Definition of H[superscript 1/2](R[superscript n]) | 181 |
7.12 | Integral formulas for (f, | 184 |
7.13 | Convexity inequality for the relativistic kinetic energy | 185 |
7.14 | Density of C[superscript infinity subscript c](R[superscript n]) in H[superscript 1/2](R[superscript n]) | 186 |
7.15 | Action of [spuare root]-[Delta] and [spuare root]-[Delta] + m[superscript 2] - m on distributions | 186 |
7.16 | Multiplication of H[superscript 1/2] functions by C[superscript infinity]-functions | 187 |
7.17 | Symmetric decreasing rearrangement decreases kinetic energy | 188 |
7.18 | Weak limits | 190 |
7.19 | Magnetic fields: The H[superscript 1 subscript A]-spaces | 191 |
7.20 | Definition of H[superscript 1 subscript A](R[superscript n]) | 192 |
7.21 | Diamagnetic inequality | 193 |
7.22 | C[superscript infinity subscript c](R[superscript n]) is dense in H[superscript 1 subscript A](R[superscript n]) | 194 |
| Exercises | 195 |
Chapter 8. | Sobolev Inequalities | 199 |
8.1 | Introduction | 199 |
8.2 | Definition of D[superscript 1](R[superscript n]) and D[superscript 1/2](R[superscript n]) | 201 |
8.3 | Sobolev's inequality for gradients | 202 |
8.4 | Sobolev's inequality for | |204 |
8.5 | Sobolev inequalities in 1 and 2 dimensions | 205 |
8.6 | Weak convergence implies strong convergence on small sets | 208 |
8.7 | Weak convergence implies a.e. convergence | 212 |
8.8 | Sobolev inequalities for W[superscript m,p]([Omega]) | 213 |
8.9 | Rellich-Kondrashov theorem | 214 |
8.10 | Nonzero weak convergence after translations | 215 |
8.11 | Poincare's inequalities for W[superscript m,p]([Omega]) | 218 |
8.12 | Poincare-Sobolev inequality for W[superscript m,p]([Omega]) | 219 |
8.13 | Nash's inequality | 220 |
8.14 | The logarithmic Sobolev inequality | 223 |
8.15 | A glance at contraction semigroups | 225 |
8.16 | Equivalence of Nash's inequality and smoothing estimates | 227 |
8.17 | Application to the heat equation | 229 |
8.18 | Derivation of the heat kernel via logarithmic Sobolev inequalities | 232 |
| Exercises | 235 |
Chapter 9. | Potential Theory and Coulomb Energies | 237 |
9.1 | Introduction | 237 |
9.2 | Definition of harmonic, subharmonic, and superharmonic functions | 238 |
9.3 | Properties of harmonic, subharmonic, and superharmonic functions | 239 |
9.4 | The strong maximum principle | 243 |
9.5 | Harnack's inequality | 245 |
9.6 | Subharmonic functions are potentials | 246 |
9.7 | Spherical charge distributions are 'equivalent' to point charges | 248 |
9.8 | Positivity properties of the Coulomb energy | 250 |
9.9 | Mean value inequality for [Delta] - [mu superscript 2] | 251 |
9.10 | Lower bounds on Schrodinger 'wave' functions | 254 |
9.11 | Unique solution of Yukawa's equation | 255 |
| Exercises | 256 |
Chapter 10. | Regularity of Solutions of Poisson's Equation | 257 |
10.1 | Introduction | 257 |
10.2 | Continuity and first differentiability of solutions of Poisson's equation | 260 |
10.3 | Higher differentiability of solutions of Poisson's equation | 262 |
Chapter 11. | Introduction to the Calculus of Variations | 267 |
11.1 | Introduction | 267 |
11.2 | Schrodinger's equation | 269 |
11.3 | Domination of the potential energy by the kinetic energy | 270 |
11.4 | Weak continuity of the potential energy | 274 |
11.5 | Existence of a minimizer for E[subscript 0] | 275 |
11.6 | Higher eigenvalues and eigenfunctions | 278 |
11.7 | Regularity of solutions | 279 |
11.8 | Uniqueness of minimizers | 280 |
11.9 | Uniqueness of positive solutions | 281 |
11.10 | The hydrogen atom | 282 |
11.11 | The Thomas-Fermi problem | 284 |
11.12 | Existence of an unconstrained Thomas-Fermi minimizer | 285 |
11.13 | Thomas-Fermi equation | 286 |
11.14 | The Thomas-Fermi minimizer | 287 |
11.15 | The capacitor problem | 289 |
11.16 | Solution of the capacitor problem | 293 |
11.17 | Balls have smallest capacity | 296 |
| Exercises | 297 |
Chapter 12. | More about Eigenvalues | 299 |
12.1 | Min-max principles | 300 |
12.2 | Generalized min-max | 302 |
12.3 | Bound for eigenvalue sums in a domain | 304 |
12.4 | Bound for Schrodinger eigenvalue sums | 306 |
12.5 | Kinetic energy with antisymmetry | 311 |
12.6 | The semiclassical approximation | 314 |
12.7 | Definition of coherent states | 316 |
12.8 | Resolution of the identity | 317 |
12.9 | Representation of the nonrelativistic kinetic energy | 319 |
12.10 | Bounds for the relativistic kinetic energy | 319 |
12.11 | Large N eigenvalue sums in a domain | 320 |
12.12 | Large N asymptotics of Schrodinger eigenvalue sums | 323 |
| Exercises | 327 |
| List of Symbols | 331 |
| References | 335 |
| Index | 341 |