Topological vacuum structure of a lattice CP3-model on T2 and S2

The topological susceptibility /V is computed for the CP3-model appropriately discretized on simplicial lattices on T2 and S2, respectively. We concentrate on volumes 1≤V/ξ2≤100, ξ being the correlation length measured on T2. Approximate scaling behaviour is found presumably not related to the continuum limit but rather to the occurence of dislocations. We observe finite-size effects which are fairly weak on the sphere, however. (orig.)