Skip to main content Accessibility help
×
Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-30T19:52:47.438Z Has data issue: false hasContentIssue false

20 - Lectures on K-theory

Published online by Cambridge University Press:  23 May 2010

Get access

Summary

In these two lectures on K-theory I shall:

  1. (i) Give the elementary proof (due to Atiyah and Bott) of the Bott periodicity theorem.

  2. (ii) Develop the basic machinery of K-theory (using Dold's lectures on half-exact functors) and show how Adams and Dyer have applied it to obtain Adams' result on the nonexistence of elements of Hopf invariant one.

I shall under (i) only give the surjectivity of the Bott homomorphism whereas the injectivity is obtained under (ii) from ‘general nonsense’. This shortens the exposition. For the full elementary proof see the notes of Atiyah and Bott distributed during this Summer Institute.

Vector bundles on X and vector bundles on X × S2

Let X be a compact topological space. We shall prove the Bott periodicity theorem by examining the relationship between complex vector bundles on X and complex vector bundles on X × s2. A complex vector bundle may have different fibre dimensions over the various connectedness components of its base space. We consider S2 as C ∪ ∞ and S1 as {z ∥ z ∣ = 1}.

If E is a complex vector bundle on X, Ex denotes the fibre of E at x ∈ X. A clutching function for E is a function p which continuously assigns to each (x, z) ∈ X × S1 an automorphism p(x, z) of Ex. An endomorphism of E is a function a which continuously assigns to each x ∈ X an endomorphism a(x) of Ex. a is an automorphism of E if a(x) is non-singular for x all x ∈ X.

Type
Chapter
Information
Algebraic Topology
A Student's Guide
, pp. 223 - 238
Publisher: Cambridge University Press
Print publication year: 1972

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×