ABSTRACT

Giving an easily accessible elementary introduction to the algebraic theory of quadratic forms, this book covers both Witt's theory and Pfister's theory of quadratic forms.
Leading topics include the geometry of bilinear spaces, classification of bilinear spaces up to isometry depending on the ground field, formally real fields, Pfister forms, the Witt ring of an arbitrary field (characteristic two included), prime ideals of the Witt ring, Brauer group of a field, Hasse and Witt invariants of quadratic forms, and equivalence of fields with respect to quadratic forms. Problem sections are included at the end of each chapter. There are two appendices: the first gives a treatment of Hasse and Witt invariants in the language of Steinberg symbols, and the second contains some more advanced problems in 10 groups, including the u-invariant, reduced and stable Witt rings, and Witt equivalence of fields.

part I|128 pages

Bilinear spaces

chapter 1|12 pages

Introduction

chapter 2|10 pages

Bilinear spaces

chapter 3|10 pages

Bases and matrices of bilinear spaces

chapter 4|12 pages

Isometries of bilinear spaces

chapter 5|16 pages

Nonsingular bilinear spaces

chapter 6|12 pages

Diagonalization of bilinear spaces

chapter 7|12 pages

Witt’s cancellation theorem

chapter 8|13 pages

Witt’s chain isometry theorem

chapter 9|11 pages

Symmetric spaces over some fields

chapter 10|16 pages

Isometry groups

part II|192 pages

Witt rings

chapter 11|16 pages

Metabolic and hyperbolic spaces

chapter 12|15 pages

Witt decomposition of symmetric spaces

chapter 13|12 pages

Witt group

chapter 14|16 pages

Tensor products

chapter 15|16 pages

Witt ring

chapter 16|22 pages

Quadratic forms

chapter 17|20 pages

Pfister forms

chapter 18|26 pages

Formally real fields and ordered fields

chapter 19|28 pages

Prime ideals of the Witt ring

chapter 20|18 pages

Witt equivalence of fields

part III|104 pages

Invariants

chapter 21|17 pages

Algebras

chapter 22|23 pages

Quaternion algebras

chapter 23|22 pages

Tensor product of algebras

chapter 24|15 pages

Brauer group

chapter 25|22 pages

Hasse and Witt invariants