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1 | (12) |
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1.1 Examples of Ergodic Behavior |
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1 | (2) |
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1.2 Equidistribution for Polynomials |
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3 | (1) |
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4 | (1) |
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1.4 Indefinite Quadratic Forms and Oppenheim's Conjecture |
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5 | (2) |
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1.5 Littlewood's Conjecture |
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7 | (1) |
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1.6 Integral Quadratic Forms |
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8 | (1) |
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1.7 Dynamics on Homogeneous Spaces |
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9 | (1) |
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1.8 An Overview of Ergodic Theory |
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10 | (3) |
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2 Ergodicity, Recurrence and Mixing |
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13 | (56) |
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2.1 Measure-Preserving Transformations |
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13 | (8) |
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21 | (2) |
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23 | (5) |
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2.4 Associated Unitary Operators |
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28 | (4) |
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2.5 The Mean Ergodic Theorem |
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32 | (5) |
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2.6 Pointwise Ergodic Theorem |
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37 | (11) |
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2.6.1 The Maximal Ergodic Theorem |
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37 | (1) |
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2.6.2 Maximal Ergodic Theorem via Maximal Inequality |
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38 | (2) |
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2.6.3 Maximal Ergodic Theorem via a Covering Lemma |
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40 | (4) |
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2.6.4 The Pointwise Ergodic Theorem |
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44 | (1) |
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2.6.5 Two Proofs of the Pointwise Ergodic Theorem |
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45 | (3) |
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2.7 Strong-Mixing and Weak-Mixing |
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48 | (6) |
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2.8 Proof of Weak-Mixing Equivalences |
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54 | (7) |
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2.8.1 Continuous Spectrum and Weak-Mixing |
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59 | (2) |
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2.9 Induced Transformations |
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61 | (8) |
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69 | (28) |
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3.1 Elementary Properties |
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69 | (7) |
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3.2 The Continued Fraction Map and the Gauss Measure |
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76 | (11) |
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3.3 Badly Approximable Numbers |
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87 | (4) |
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88 | (3) |
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3.4 Invertible Extension of the Continued Fraction Map |
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91 | (6) |
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4 Invariant Measures for Continuous Maps |
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97 | (24) |
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4.1 Existence of Invariant Measures |
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98 | (5) |
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4.2 Ergodic Decomposition |
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103 | (2) |
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105 | (5) |
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4.4 Measure Rigidity and Equidistribution |
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110 | (11) |
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4.4.1 Equidistribution on the Interval |
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110 | (3) |
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4.4.2 Equidistribution and Generic Points |
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113 | (1) |
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4.4.3 Equidistribution for Irrational Polynomials |
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114 | (7) |
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5 Conditional Measures and Algebras |
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121 | (32) |
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5.1 Conditional Expectation |
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121 | (5) |
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126 | (7) |
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133 | (12) |
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145 | (8) |
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153 | (18) |
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6.1 The Ergodic Theorem and Decomposition Revisited |
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153 | (3) |
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6.2 Invariant Algebras and Factor Maps |
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156 | (2) |
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158 | (1) |
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159 | (4) |
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6.5 Constructing Joinings |
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163 | (8) |
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7 Furstenberg's Proof of Szemeredi's Theorem |
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171 | (60) |
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172 | (3) |
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175 | (3) |
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7.2.1 Reduction to an Invertible System |
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177 | (1) |
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7.2.2 Reduction to Borel Probability Spaces |
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177 | (1) |
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7.2.3 Reduction to an Ergodic System |
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177 | (1) |
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7.3 Furstenberg Correspondence Principle |
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178 | (2) |
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7.4 An Instance of Polynomial Recurrence |
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180 | (8) |
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7.4.1 The van der Corput Lemma |
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184 | (4) |
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7.5 Two Special Cases of Multiple Recurrence |
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188 | (4) |
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188 | (2) |
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7.5.2 Weak-Mixing Systems |
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190 | (2) |
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192 | (7) |
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7.6.1 Proof of Theorem 7.14 for a Kronecker System |
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194 | (1) |
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7.6.2 Reducing the General Case to the Kronecker Factor |
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195 | (4) |
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199 | (2) |
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7.8 Dichotomy Between Relatively Weak-Mixing and Compact Extensions |
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201 | (6) |
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7.9 SZ for Compact Extensions |
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207 | (9) |
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7.9.1 SZ for Compact Extensions via van der Waerden |
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210 | (2) |
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212 | (4) |
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7.10 Chains of SZ Factors |
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216 | (2) |
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7.11 SZ for Relatively Weak-Mixing Extensions |
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218 | (8) |
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7.12 Concluding the Proof |
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226 | (1) |
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7.13 Further Results in Ergodic Ramsey Theory |
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227 | (4) |
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7.13.1 Other Furstenberg Ergodic Averages |
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227 | (4) |
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8 Actions of Locally Compact Groups |
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231 | (46) |
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8.1 Ergodicity and Mixing |
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231 | (4) |
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8.2 Mixing for Commuting Automorphisms |
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235 | (8) |
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8.2.1 Ledrappier's "Three Dots" Example |
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236 | (3) |
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8.2.2 Mixing Properties of the x2, x3 System |
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239 | (4) |
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8.3 Haar Measure and Regular Representation |
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243 | (8) |
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8.3.1 Measure-Theoretic Transitivity and Uniqueness |
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245 | (6) |
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251 | (3) |
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8.4.1 Definition of Amenability and Existence of Invariant Measures |
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251 | (3) |
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8.5 Mean Ergodic Theorem for Amenable Groups |
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254 | (3) |
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8.6 Pointwise Ergodic Theorems and Polynomial Growth |
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257 | (9) |
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257 | (2) |
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8.6.2 Pointwise Ergodic Theorems for a Class of Groups |
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259 | (7) |
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8.7 Ergodic Decomposition for Group Actions |
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266 | (6) |
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272 | (5) |
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9 Geodesic Flow on Quotients of the Hyperbolic Plane |
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277 | (54) |
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9.1 The Hyperbolic Plane and the Isometric Action |
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277 | (5) |
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9.2 The Geodesic Flow and the Horocycle Flow |
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282 | (6) |
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9.3 Closed Linear Groups and Left Invariant Riemannian Metric |
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288 | (17) |
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9.3.1 The Exponential Map and the Lie Algebra of a Closed Linear Group |
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289 | (6) |
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9.3.2 The Left-Invariant Riemannian Metric |
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295 | (6) |
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9.3.3 Discrete Subgroups of Closed Linear Groups |
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301 | (4) |
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9.4 Dynamics on Quotients |
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305 | (9) |
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9.4.1 Hyperbolic Area and Fuchsian Groups |
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306 | (4) |
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9.4.2 Dynamics on I\PSL2(R) |
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310 | (1) |
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9.4.3 Lattices in Closed Linear Groups |
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311 | (3) |
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9.5 Hopf's Argument for Ergodicity of the Geodesic Flow |
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314 | (3) |
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9.6 Ergodicity of the Gauss Map |
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317 | (10) |
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9.7 Invariant Measures and the Structure of Orbits |
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327 | (4) |
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327 | (1) |
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9.7.2 Measures Coming from Orbits |
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328 | (3) |
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331 | (16) |
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10.1 Rotations on the Quotient of the Heisenberg Group |
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331 | (2) |
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333 | (1) |
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10.3 First Proof of Theorem 10.1 |
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334 | (2) |
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10.4 Second Proof of Theorem 10.1 |
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336 | (5) |
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10.4.1 A Commutative Lemma; The Set K |
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336 | (1) |
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10.4.2 Studying Divergence; The Set X1 |
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337 | (2) |
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10.4.3 Combining Linear Divergence and the Maximal Ergodic Theorem |
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339 | (2) |
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10.5 A Non-ergodic Nilrotation |
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341 | (1) |
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10.6 The General Nilrotation |
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342 | (5) |
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11 More Dynamics on Quotients of the Hyperbolic Plane |
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347 | (56) |
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347 | (10) |
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11.2 Examples of Lattices |
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357 | (7) |
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11.2.1 Arithmetic and Congruence Lattices in SL2 (R) |
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358 | (1) |
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11.2.2 A Concrete Principal Congruence Lattice of SL2 (R) |
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358 | (3) |
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361 | (3) |
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11.3 Unitary Representations, Mautner Phenomenon, and Ergodicity |
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364 | (6) |
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11.3.1 Three Types of Actions |
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364 | (2) |
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366 | (3) |
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11.3.3 Mautner Phenomenon for SL2(R) |
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369 | (1) |
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11.4 Mixing and the Howe---Moore Theorem |
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370 | (8) |
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11.4.1 First Proof of Theorem 11.22 |
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370 | (2) |
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11.4.2 Vanishing of Matrix Coefficients for PSL2(R) |
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372 | (1) |
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11.4.3 Second Proof of Theorem 11.22; Mixing of All Orders |
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372 | (6) |
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11.5 Rigidity of Invariant Measures for the Horocycle Flow |
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378 | (10) |
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11.5.1 Existence of Periodic Orbits; Geometric Characterization |
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379 | (4) |
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11.5.2 Proof of Measure Rigidity for the Horocycle Flow |
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383 | (5) |
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11.6 Non-escape of Mass for Horocycle Orbits |
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388 | (11) |
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11.6.1 The Space of Lattices and the Proof of Theorem 11.32 for X2 = SL2(Z)\SL2(R) |
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390 | (5) |
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11.6.2 Extension to the General Case |
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395 | (4) |
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11.7 Equidistribution of Horocycle Orbits |
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399 | (4) |
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Appendix A Measure Theory |
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403 | (14) |
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403 | (3) |
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406 | (1) |
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407 | (2) |
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A.4 Radon-Nikodym Derivatives |
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409 | (1) |
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410 | (1) |
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A.6 Well-Behaved Measure Spaces |
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411 | (1) |
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A.7 Lebesgue Density Theorem |
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412 | (1) |
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413 | (4) |
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Appendix B Functional Analysis |
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417 | (12) |
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417 | (1) |
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418 | (1) |
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419 | (2) |
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421 | (1) |
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B.5 Measures on Compact Metric Spaces |
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422 | (3) |
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B.6 Measures on Other Spaces |
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425 | (1) |
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B.7 Vector-valued Integration |
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425 | (4) |
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Appendix C Topological Groups |
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429 | (12) |
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429 | (2) |
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C.2 Haar Measure on Locally Compact Groups |
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431 | (2) |
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433 | (8) |
Hints for Selected Exercises |
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441 | (6) |
References |
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447 | (16) |
Author Index |
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463 | (4) |
Index of Notation |
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467 | (4) |
General Index |
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471 | |