作為作者獲獎書Algebraic Theory of Quadratic Forms (Benjamin, 1973) 的新版,本書給出了在特征非 2 的任意域上的二次型理論的一個現(xiàn)代、自足的導引。從除了線性代數(shù)外的少量預備知識出發(fā),作者講述了一個專家級的課程,內容從二次型的Witt經(jīng)典理論、四元數(shù)與Clifford 代數(shù)、形式實域的 Artin-Schreier理論、Witt 環(huán)的結構定理,到 Pfister形式理論、函數(shù)域和域不變量。這些主要進展與所涉及的 Brauer-Wall 群、局部與整體域、跡形式、Galois理論以及初等代數(shù) K-理論天衣無縫地交織在一起,對域上二次型理論做了一個獨一無二的原創(chuàng)性處理。新版中增加了超過100頁全新的兩章,內容包括這個領域中更新的結果以及更加近代的觀點。 作為作者寫作的特點,本書主要內容的陳述總是穿插大量精心挑選的解釋一般理論的例題。這個特點再加上全部十三章280多個內容豐富的習題,極大提升了本書的價值,使得本書可以作為代數(shù)、數(shù)論、代數(shù)幾何、代數(shù)拓撲以及幾何拓撲研究者的參考書。
Preface
Notes to the Reader
Partial List of Notations
Chapter I. Foundations
1. Quadratic Forms and Quadratic Spaces
2. Diagonalization of Quadratic Forms
3. Hyperbolic Plane and Hyperbolic Spaces
4. Decomposition Theorem and Cancellation Theorem
5. Witt's Chain Equivalence Theorem
6. Kronecker Product of Quadratic Spaces
7. Generation of the Orthogonal Group by Reflections
Exercises for Chapter I
Chapter II. Introduction to Witt Rings
1. Definition of W(F) and W(F)
2. Group of Square Classes
3. Some Elementary Computations
4. Presentation of Witt Rings
5. Classification of Small Witt Rings
Exercises for Chapter II
Chapter III. Quaternion Algebras and their Norm Forms
1. Construction of Quaternion Algebras
2. Quaternion Algebras as Quadratic Spaces
3. Coverings of the Orthogonal Groups
4. Linkage of Quaternion Algebras
5. Characterizations of Quaternion Algebras Exercises for Chapter III
Chapter IV. The Brauer-Wall Group
1. The Brauer Group
2. Central Simple Graded Algebras (CSGA)
3. Structure Theory of CSGA
4. The Brauer-Wall Group Exercises for Chapter IV
Chapter V. Clifford Algebras
1. Construction of Clifford Algebras
2. Structure Theorems
3. The Clifford Invariant, Witt Invariant, and Hasse Invariant
4. Real Periodicity and Clifford Modules
5. Composition of Quadratic Forms
6. Steinberg Symbols and Milnor's Group k2F
Exercises for Chapter V
Chapter VI. Local Fields and Global Fields
1. Springer's Theorem for C.D.V. Fields
2. Quadratic Forms over Local Fields
Appendix: Nonreal Fields with Four Square Classes
3. Hasse-Minkowski Principle
4. Witt Ring of Q
5. Hilbert Reciprocity and Quadratic Reciprocity
Exercises for Chapter VI
Chapter VII. Quadratic Forms Under Algebraic Extensions
1. Scharlau's Transfer
2. Simple Extensions and Springer's Theorem
3. Quadratic Extensions
4. Scharlau's Norm Principle
5. Knebusch's Norm Principle
6. Galois Extensions and Trace Forms
7. Quadratic Closures of Fields
Exercises for Chapter VII
Chapter VIII. Formally Real Fields, Real-Closed Fields, and Pythagorean Fields
1. Structure of Formally Real Fields
2. Characterizations of Real-Closed Fields
Appendix A: Uniqueness of Real-Closure
Appendix B: Another Artin-Schreier Theorem
3. Pfister's Local-Global Principle
4. Pythagorean Fields
Appendix: Fields with 8 Square Classes and 20rderings
5. Connections with Galois Theory
6. Harrison Topology on XF
7. Prime Spectrum of W(F)
8. Applications to the Structure of W(F)
9. An Introduction to Preorderings
Exercises for Chapter VIII
Chapter IX. Quadratic Forms under Transcendental Extensions
1. Cassels-Pfister Theorem
2. Second and Third Representation Theorems
3. Milnor's Exact Sequence for W(F(x))
4. Scharlau's Reciprocity Formula for F(x)
Exercises for Chapter IX
Chapter X. Pfister Forms and Function Fields
1. Chain P-Equivalence
Appendix: Round Forms
2. Multiplicative Forms
3. Introduction to Function Fields
4. Basic Theorems on Function Fields
5. Hanptsatz, Linkage, and Forms in InF
6. Milnor's Higher K-Groups Exercises for Chapter X
Chapter XI. Field Invariants
1. Sums of Squares
2. The Level of a Field
3. Pfister-Witt Annihilator Theorem
4. The Property (An)
5. Height and Pythagoras Number
6. The u-Invariant of a Field
Appendix: The General u-Invariant
7. The Size of W(F), and C-Fields
Exercises for Chapter XI
Chapter XII. Special Topics in Quadratic Forms
1. Isomorphisms of Witt Rings
2. Quadratic Forms of Low Dimension
Appendix: Forms with Isomorphic Function Fields
3. Some Classification Theorems
4. Witt Rings under Biquadratic Extensions
5. Nonreal Fields with Eight Square Classes
6. Kaplansky Radical and Hilbert Fields
7. Construction of Some Pre-Hilbert Fields
8. Axiomatic Schemes for Quadratic Forms
Exercises for Chapter XII
Chapter XIII. Special Topics on Invariants
1. The u-Invariant of C((x, y))
2. Fields of u-Invariant 6
3. Fields of Pythagoras Number 6 and 7
4. Levels of Commutative Rings
5. Pythagoras Numbers of Commutative Rings
6. Some Open Questions
Exercises for Chapter XIII
Bibliography
Index