  The O(3) sigma model and abelian Higgs model in two space dimensions admit
topological (Bogomol'nyi) lower bounds on their energy. This paper proposes
lattice versions of these systems which maintain the Bogomol'nyi bounds. One
consequence is that instantons/solitons/vortices on the lattice then have a
high degree of stability.

High Energy Physics - Theory;High Energy Physics - Lattice