Central Simple Algebras and Galois Cohomology by Philippe Gille

By Philippe Gille

This publication is the 1st complete, glossy advent to the idea of primary easy algebras over arbitrary fields. ranging from the fundamentals, it reaches such complex effects because the Merkurjev-Suslin theorem. This theorem is either the end result of labor initiated by means of Brauer, Noether, Hasse and Albert and the place to begin of present study in motivic cohomology idea via Voevodsky, Suslin, Rost and others. Assuming just a stable heritage in algebra, yet no homological algebra, the e-book covers the fundamental idea of relevant basic algebras, equipment of Galois descent and Galois cohomology, Severi-Brauer forms, residue maps and, ultimately, Milnor K-theory and K-cohomology. The final bankruptcy rounds off the speculation through providing the implications in confident attribute, together with the theory of Bloch-Gabber-Kato. The publication is appropriate as a textbook for graduate scholars and as a reference for researchers operating in algebra, algebraic geometry or K-theory.

Show description

Read or Download Central Simple Algebras and Galois Cohomology PDF

Similar topology books

Topology and Geometry (Graduate Texts in Mathematics, Volume 139)

Uploader's word: Ripped from SpringerLink.

This e-book deals an introductory path in algebraic topology. beginning with basic topology, it discusses differentiable manifolds, cohomology, items and duality, the elemental workforce, homology thought, and homotopy thought.

From the experiences: "An attention-grabbing and unique graduate textual content in topology and geometry. .. a very good lecturer can use this article to create a superb direction. .. .A starting graduate pupil can use this article to benefit loads of arithmetic. "—-MATHEMATICAL experiences

Central Simple Algebras and Galois Cohomology

This e-book is the 1st accomplished, glossy advent to the speculation of imperative easy algebras over arbitrary fields. ranging from the fundamentals, it reaches such complicated effects because the Merkurjev-Suslin theorem. This theorem is either the fruits of labor initiated via Brauer, Noether, Hasse and Albert and the start line of present study in motivic cohomology conception through Voevodsky, Suslin, Rost and others.

Introduction to Topology: Third Edition

Very popular for its unheard of readability, creative and instructive workouts, and superb writing sort, this concise e-book bargains a fantastic introduction to the basics of topology. It presents an easy, thorough survey of straight forward issues, beginning with set conception and advancing to metric and topological spaces, connectedness, and compactness.

Extra resources for Central Simple Algebras and Galois Cohomology

Sample text

In this way we associate with (V, ) a K -object (VK , K ). 3 Galois descent 25 between (VK , K ) and (W K , K ). In this situation, (W, ) is also called a (K |k)-twisted form of (V, ) or a twisted form for short. Now Galois theory enables one to classify k-isomorphism classes of twisted forms as follows. Given a k-automorphism σ : K → K , tensoring by V gives a k-automorphism VK → VK which we again denote by σ . Each K -linear map f : VK → W K induces a map σ ( f ) : VK → W K defined by σ ( f ) = σ ◦ f ◦ σ −1 .

Induces an isomorphism k × → 1 Central simple algebras and Galois descent 44 Proof We first show surjectivity. e. by multiplication with suitable elementary matrices. Thus by Whitehead’s lemma each element of K 1 (k) may be represented by some diagonal matrix. But any diagonal matrix may be expressed as a product of a diagonal matrix of the form diag(b, 1, . . , 1) and diagonal matrices of the form diag(1, . . , 1, a, a −1 , 1, . . , 1). The same matrix calculation that establishes formula (9) shows that the latter are products of elementary matrices, so the class in K 1 (k) is represented by diag(b, 1, .

Wn is a k-basis of K , then 1 ⊗ w1 , . . , 1 ⊗ wn yields a D-basis of D ⊗k K as a left D-vector space. Given an element x = αi (1 ⊗ wi ) in the centre of D ⊗k K , for all d ∈ D the relation x = (d −1 ⊗ 1)x(d ⊗ 1) = (d −1 αi d)(1 ⊗ wi ) implies d −1 αi d = αi by the linear independence of the 1 ⊗ wi . As D is central over k, the αi must lie in k, so D ⊗k K is central over K . Now if J is a nonzero ideal in D ⊗k K generated by elements z 1 , . . 2 Splitting fields 21 D-linearly independent and extend them to a D-basis of D ⊗k K by adjoining some of the 1 ⊗ wi , say 1 ⊗ wr +1 , .

Download PDF sample

Rated 4.50 of 5 – based on 14 votes