On monopoles' symmetry and other concerns

[Redsummers]

Ok so, I have a few question regarding the symmetry and other properties of the magnetic monopoles.

I see how they actually arise from a mathematical symmetry of Maxwell equations, but my first question is: if they were discovered to exist (experimentally speaking), would there be no need in particle physics to research supersymmetry and so on?
–I have heard somehow that if Monopoles were to be observed; a lot of physics would be automatically over, is that so?

Another question I have, is concerning the 'Dirac's condition'. What do they actually mean by 'if there was a single monopole to be found in the universe, this would imply the quantization (??) of the electric charge'?

As a last question, I would like to know how are the 'new theories' in particle physics treating monopoles. Do they assume their existence? How about other mainstream theories? In the case that their existence is not assumed, why 't Hooft and others have developed other definitions of monopoles? (or those topological defects are nothing more than mere mathematical anecdotes for physicists?)



Any input is greatly appreciated!

P.S. I have checked other threads where Monopoles have been the topic of discussion, but I couldn't find any information concerning my doubts. So, sorry if this is sort of time line.

 

[Bill_K]

I believe you'll find a good discussion of the magnetic monopole including Dirac's quantization condition on Wikipedia.

 

[Feldoh]

Another question I have, is concerning the 'Dirac's condition'. What do they actually mean by 'if there was a single monopole to be found in the universe, this would imply the quantization (??) of the electric charge'?

Dirac was one of the first people of look at monopoles in-depth. As you pointed out, Maxwell's equations exhibit a lot of symmetry and it makes some sort of sense that we should see magnetic monopoles.

Well, Dirac went out of see what would happen to Maxwell's equations if we assumed that magnetic monopoles were to exist. As it turns out that in order for Maxwell's equations to still hold with magnetic monopoles we the electric charge to be quantized. That is what people mean by that statement. It simply means that for the mathematics of Maxwell's equations to work with magnetic monopoles electric charge needs to be quantized.