Are M2 and M5 membranes in M-Theory excited states of some underlying field, or are they fundamental? In what sense are membranes solitonic?
In the reference question, someone made a comment that had no reply and I am just as curious
"My question is, what is the M brane itself? Is there an underlying M brane field where the branes are excitations of the field? Or is the M brane simply a fundamental object made out of no fields?"
I am confused what an M Brane really is. M2 membranes are strings when you compatify a membrane on a circle, if I am not wrong, so this means all strings and branes are really just solitons?