Wrapped Branes and Confined Momentum
  We present string-like soliton solutions of three-dimensional gravity, coupled to a compact scalar field $x^{11}$ and Kaluza-Klein reduced on a circle. These solitons carry fractional magnetic flux with respect to the Kaluza-Klein gauge field. Summing over such ``Kaluza-Klein flux tubes'' is shown to imply summing over a subclass of three-dimensional topologies (Seifert manifolds). It is also shown to imply an area law for the Wilson loop of the Kaluza-Klein gauge field; the confined charge is nothing but Kaluza-Klein momentum. Applied to the membrane of M-theory, this is interpreted as ``dynamical wrapping'' of the M-brane around its eleventh embedding dimension $x^{11}$. 
Christof Schmidhuber