Are monopoles a problem for all gauge groups in GUT theories?

[emanaly]

Hi All
I have some questions about monopoles, I would be grateful if someone help me in answering them.
1-Does all GUTs gauge groups simple and semi simple suffer from the monopoles problem?
2- If semi simple groups suffer from the above problem why standard Model doesn't produce monoples although there will be U(1) electromagnetic group when spontanous breaking happens?
Eman

 

[blechman]

Hi All
I have some questions about monopoles, I would be grateful if someone help me in answering them.
1-Does all GUTs gauge groups simple and semi simple suffer from the monopoles problem?

many of them do.

2- If semi simple groups suffer from the above problem why standard Model doesn't produce monoples although there will be U(1) electromagnetic group when spontanous breaking happens?
Eman

It does! Well, EWSB won't since there's a U(1) hypercharge, but for example, SU(5) GUT theories should produce monopoles. In fact, this was the original motivation for inflation - to push them all out of causal contact with us.

 

[Haelfix]

It should be that nonperturbative physics in many gauge theories already include these objects, for instance in various supersymmetric field theories and others. So they are far from just being a signature of GUT physics perse.