Group consists of a set and an operation

[greatscott]

When physicists say "elementary particles form a group," what kind of operations and sets are in question? (I presume, a group consists of a set and an operation)

 

[greatscott]

Ok, the operation for SU(n) is always matrix multiplication.
Now my next question is, what kind of matrices are concerned? What do the elements of the matrices represent?

 

[dextercioby]

Nope,u missunderstood.They do not form a group,they are irreductible representations of continuous groups...To fully understand it,u must know group theory and their representations...

Daniel.

 

[greatscott]

So the continuous group has all the information and things like spin (SU(2)) are just "parts" of it?

 

[marlon]

I have written all this in my journal. Just look for the "introduction to string theory"-entry, part one. There is a paragraphe especially dedicated to how field theories are constructed using global and local symmetries...When imposing such local symmetries, gauge-particles arise...Check it out, it is all in there

regards
marlon