Topology and metastability in the lattice Skyrme model - art. no. 114020

We offer the Skyrme model on a lattice as an effective field theory-fully q uantized-of baryon-meson interactions at temperatures below the chiral phas e transition. We define a local topological density that involves the volum es of tetrahedra in the target space S-3 and we make use of Coxeter's formu la for the Schlafli function to implement it. This permits us to calculate the mean-square radius of a Skyrmion in the three-dimensional lattice Skyrm e model, which may be viewed as a Ginzburg-Landau effective theory for the full quantum theory at finite temperature. We find that, contrary to expect ations, the Skyrmion shrinks as quantum and thermal fluctuations are enhanc ed. We ascribe this to a large number of metastable states th:lt become acc essible as the temperature is raised.