Generalizing the kink operator of the Heisenberg spin 1/2 model, we construct a set of Klein factors explicitly such that (1 + 1) dimensional fermion theories with arbitrary number of species are mapped onto the corresponding boson theories with the same number of species and vice versa. The actions for the resultant theories do not possess any nontrivial Klein factor. With this set of Klein fa...

Magnetic fields in five-dimensional Kaluza-Klein theory compactified on a circle correspond to “twisted” identifications of five dimensional Minkowski space. We show that a five dimensional generalisation of the Kerr solution can be analytically continued to construct an instanton that gives rise to two possible decay modes of a magnetic field. One decay mode is the generalisation of the “bubbl...