Induced fermion number and quantum mechanical stability of solitonic objects"

It is known that topological solutions in gauge field theories can carry fermionic zero energy modes. In this case the presence of the zero-energy modes induces a fermionic charge on the background solution. This induced charge can have non-integer values. We have explored semi-classical solutions which are only metastable but can nevertheless carry fermionic zero-energy modes. These modes in turn can induce fractional fermion number. We show that as a result, a meta-stable configuration of bosonic fields in fact becomes stable. The result is shown to hold even when the coupled fermions are majorana and do not themselves carry a conserved fermion number.