gauge group
The first objective is to show how to create a bundle called . There are two different ways to do this. The first way is to observe that since for vector spaces that (here just meaning the module of homomorphisms from to ) thus if we take the bundle then we have that since the fibers we have what we want.
Another way of looking at the creation of the bundle is to look at representations and what we would ideally like our bundle to look like. If we have that the bundle that represents is given by taking the principle bundle
and a trivial representation then the bundle afforded by the trivial representation is simply . The same thing is true with the bundle . We then have that if we look at the structure group of our proposed new bundle it should be . The fibers of our proposed new bundle definitely should be thus we have that the representation we are looking for should take something in our structure group and something in the fiber and give us something new in the fiber. The proposed representation is . Then looking at the bundle associated to the representation of gives us that if
then
we can similarly define
The group of sections of is called the gauge group. It is a group since we have that if is a section of and is also a section of then we have a group operation given by composition:
The fact that these bundle maps are isomorphisms of bundles gives the existence of an inverse. The reason for this is that for each section , since is a vector space isomorphism. Thus we now have that if we look at the bundle map given by taking (where means for each ). Associativity is clear by composition of functions being associative and the identity map acts as the identity element.
Title | gauge group |
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Canonical name | GaugeGroup |
Date of creation | 2013-03-22 17:02:34 |
Last modified on | 2013-03-22 17:02:34 |
Owner | sjm1979 (13837) |
Last modified by | sjm1979 (13837) |
Numerical id | 9 |
Author | sjm1979 (13837) |
Entry type | Definition |
Classification | msc 55R25 |
Defines | bundle of homomorphisms |
Defines | bundle of endomorphisms |
Defines | automorphism bundle |