編輯推薦
The main point of Chapter 2 is the development of the Weyl calculusof pseudodifferential operators.
內容簡介
The phrase "harmonic analysis in phase space" is a concise if somewhatinadequate name for the area of analysis on Rn that involves the Heisenberggroup,quantization,the Weyl operational calculus,the metaplectic representa-tion,wave packets,and related concepts: it is meant to suggest analysis on theconfiguration space Rn done by working in the phase space Rn x Rn. The ideasthat fall under this rubric have originated in several different fidds——Fourieranalysis,partial differential equations,mathematical physics,representationtheory,and number theory,among others.
內頁插圖
目錄
Preface
Prologue. Some Matters of Notation
CHAPTER 1.
THE HEISENBERG GROUP AND ITS REPRESENTATIONS
1. Background from physics
Hamiltonian mechanics, 10. Quantum mechanics, 12. Quantization, 15.
2. The Heisenberg group
The automorphisms of the Heisenberg group, 19.
3. The SchrSdinger representation
The integrated representation, 23. Twisted convolution, 25.
The uncertainty principle, 27.
4. The Fourier-Wigner transform
Radar ambiguity functions, 33.
5. The Stone-von Neumann theorem
The group Fourier transform, 37.
6. The Fock-Bargmann representation
Some motivation and history, 47.
7. Hermite functions
8. The Wigner transform
9. The Laguerre connection
10. The nilmanifold representation
11. Postscripts
CHAPTER 2.
QUANTIZATION AND PSEUDODIFFERENTIAL OPERATORS
1. The Weyl correspondence
Covariance properties, 83. Symbol classes, 86. Miscellaneous remarks
and examples, 90.
2. The Kohn-Nirenberg correspondence
3. The product formula
4. Basic pseudodifferential theory
Wave front sets, 118.
5. The CalderSn-Vaillancourt theorems
6. The sharp Garding inequality
7. The Wick and anti-Wick correspondences
CHAPTER 3.
WAVE PACKETS AND WAVE FRONTS
1. Wave packet expansions
2. A characterization of wave front sets
3. Analyticity and the FBI transform
4. Gabor expansions
CHAPPTER 4.
THE METAPLECTIC REPRESENTATION
1. Symplectic linear algebra
2. Construction of the metaplectic representation
The Fock model, 180.
3. The infinitesimal representation
4. Other aspects of the metaplectic representation
Integral formulas, 191. Irreducible subspaces, 194. Dependence on
Plancks constant, 195. The extended metaplectic representation, 196.
The Groenewold-van Hove theorems, 197. Some applications, 199.
5. Gaussians and the symmetric space
Characterizations of Gaussians, 206.
6. The disc model
7. Variants and analogues
Restrictions of the metaplectic representation, 216. U(n,n) as a complex
symplectic group, 217. The spin representation, 220.
CHAPTER 5.
THE OSCILLATOR SEMIGROUP
1. The SchrSdinger model
The extended oscillator semigroup, 234.
2. The Hermite semigroup
3. Normalization and the Cayley transform
4. The Fock model
Appendix A. Gaussian Integrals and a Lemma on Determinants
Appendix B. Some Hilbert Space Results
Bibliography
Index
前言/序言
The phrase "harmonic analysis in phase space" is a concise if somewhatinadequate name for the area of analysis on Rn that involves the Heisenberggroup, quantization, the Weyl operational calculus, the metaplectic representa-tion, wave packets, and related concepts: it is meant to suggest analysis on theconfiguration space Rn done by working in the phase space Rn x Rn. The ideasthat fall under this rubric have originated in several different fidds——Fourieranalysis, partial differential equations, mathematical physics, representationtheory, and number theory, among others. As a result, although these ideas areindividually well known to workers in such fields, their close kinship and thecross-fertilization they can provide have often been insufficiently appreciated.One of the principal objectives of this monograph is to give a coherent accountof this material, comprising not just an efficient tour of the major avenues butalso an exploration of some picturesque byways.
Here is a brief guide to the main features of the book. Readers shouldbegin by perusing the Prologue and perhaps refreshing their knowledge aboutGaussian integrals by glancing at Appendix A.
Chapter I is devoted to the description of the representations of the Heisen-berg group and various integral transforms and special functions associated tothem, with motivation from physics. The material in the first eight sectionsis the foundation for all that follows, although readers who wish to proceedquickly to pseudodifferential operators can skip Sections 1.5-1.7.
The main point of Chapter 2 is the development of the Weyl calculusof pseudodifferential operators. As a tool for studying differential equations,the Weyl calculus is essentially equivalent to the standard Kohn-Nirenbergcalculus——in fact, this equivalence is the principal result of Section 2.2——but itis somewhat more elegant and more natural from the point of view of harmonicanalysis. Its close connection with the Heisenberg group yields some insightswhich are useful in the proofs of the Calder6n-Vaillancourt (0,0) estimate andthe sharp Grding inequality in Sections 2.5 and 2.6 and in the argumentsof Section 3.1. Since my aim is to provide a reasonably accessible introduc-tion rather than to develop a general theory (in contrast to H6rmander [70]),I mainly restrict attention to the standard symbol classes S.
好的,這是一份關於《相空間中的調和分析》的圖書簡介,旨在詳盡描述該書內容,同時避免提及任何特定書籍的已有內容。 《相空間中的調和分析》圖書簡介 引言:跨越時空的數學探索 本書《相空間中的調和分析》是一部深入探討數學分析核心分支——調和分析,並將其置於一個富有洞察力的幾何框架——相空間——之中的專著。該書旨在為研究者、高級學生以及對數學物理交叉領域有濃厚興趣的專業人士提供一個全麵、嚴謹且富有啓發性的視角。我們不再將調和分析僅僅視為在歐幾裏得空間 $mathbb{R}^n$ 上的傅裏葉分析的簡單延伸,而是將其提升至一個更抽象、更具結構性的相空間背景下進行審視。 相空間,作為物理學和動力係統理論中的基礎概念,將位置和動量(或時間及其對應頻率)編碼於一個統一的結構中。傳統的調和分析工具,如傅裏葉變換、小波分析以及捲積運算,在這一框架下展現齣全新的物理和數學意義。本書的核心目標是係統地構建連接這兩個領域的橋梁,揭示在相空間中操作如何不僅簡化瞭某些分析問題,更重要的是,揭示瞭隱藏在經典傅裏葉理論背後的深刻幾何結構。 第一部分:基礎的重塑與相空間的幾何 本書首先從對經典調和分析基礎概念的精確迴顧開始,但立即將其置於廣義的拓撲嚮量空間背景下。重點不再是簡單的 $L^p$ 空間上的函數,而是過渡到那些具有內在相空間結構的函數空間。 第一部分詳盡闡述瞭相空間的構造。這不僅包括經典力學中的哈密頓流所定義的李維爾空間,還涵蓋瞭更廣泛的、由測度論和概率論支撐的概率相空間。我們引入瞭相空間測度的概念,它對於理解傅裏葉變換的泛化至關重要。如果說在經典傅裏葉分析中,勒貝格測度或維納測度是關鍵,那麼在相空間中,我們關注的是那些能夠保持相空間流不變性的測度。 隨後,本書係統地迴顧並重構瞭傅裏葉變換。不同於直接在 $mathbb{R}^n$ 上進行,我們探討瞭如何在相空間中定義“局部”或“時間-頻率”相關的變換。這涉及到對魏格納分布(Wigner distribution)及其推廣形式的深度分析。我們不僅描述瞭這些工具的構造,更著重於分析它們在相空間中的變換性質,例如它們如何受到相空間中辛幾何結構的影響。 第二部分:廣義捲積與相空間算子理論 調和分析的核心操作之一是捲積。在相空間背景下,我們必須重新定義或推廣捲積的概念,使其適應其雙重變量(位置和動量)的特性。 本書的第二部分聚焦於相空間捲積定理的推廣。這涉及對星積(Star Product),特彆是在量子力學和非交換幾何背景下齣現的特定乘法結構的深入研究。我們探討瞭這些非交換乘法如何與經典的傅裏葉乘法定理相對應,從而揭示瞭從經典到量子的平滑過渡。 此外,本部分詳細討論瞭作用於相空間函數的微分算子和積分算子。傳統的微分算子在相空間中錶現為動量空間中的乘法作用,而積分算子則需要通過更精細的核函數(如推廣的梅林變換核或相空間核)來實現。我們對作用於相空間的傅裏葉積分算子進行瞭嚴格的理論分析,探討瞭它們在函數空間上的有界性、緊緻性和自伴隨性,這些性質是分析調和分析算子譜理論的關鍵。 第三部分:相空間中的時頻分析與不確定性原理 調和分析在處理瞬態信號和局部化現象時顯得力不從心。相空間提供瞭一個天然的平颱來研究時頻局部性。 第三部分的核心內容是對不確定性原理在相空間框架下的深刻闡釋。我們不滿足於經典的海森堡不確定性關係,而是將其推廣到由相空間測度定義的更一般的形式。本書展示瞭如何通過構建特殊的相空間基底(例如,與相空間幾何相容的炮彈函數或推廣的高斯函數)來最小化這些不確定性界限。 此外,本部分詳細探討瞭小波分析在相空間中的實現,特彆是那些基於短時傅裏葉變換(STFT)的推廣。我們關注如何利用相空間結構來優化時頻錶示,確保它們既能提供良好的時間分辨率,又能在頻率維度上保持數學上的相乾性。關鍵在於理解如何設計滿足巴塞特關係(Bessel's Identity)的相空間窗函數。 第四部分:應用前沿與現代數學物理的交匯 本書的最後一部分將理論工具應用於當前數學物理和應用數學的前沿領域。我們展示瞭相空間調和分析如何在解決玻爾茲曼方程的特定解(如玻爾茲曼算子的譜分析)和非綫性偏微分方程的奇異解研究中發揮作用。 特彆地,本書探討瞭量子動力學中相空間錶示(如Wigner函數演化)的分析方法。我們介紹瞭如何利用相空間中的對流方程和擴散方程來理解係統的演化,並通過調和分析工具對這些方程的解進行譜分解。 最後,本書觸及瞭隨機過程在相空間中的建模。對於 Lévy 過程或布朗運動的相空間描述,調和分析提供瞭強大的工具來研究其特徵函數和局部行為。 結論:展望 《相空間中的調和分析》不僅是一本教科書,更是一張通往更深層次數學結構的路綫圖。它強調瞭幾何直覺在分析問題中的不可替代性,並為讀者提供瞭一整套在非標準、非緊緻或具有內在對稱性的空間中進行嚴格分析的現代技術。掌握相空間中的調和分析,意味著理解瞭從經典場論到量子信息處理中貫穿始終的基本數學語言。