  A new approach to the problem of topological freezing in gauge theories is
introduced in which a physical volume preserving coarsening of the lattice
induces sufficient energy variation in the Hamiltonian to overcome large
topological barriers. Though the process is not reversible, the physical volume
preserving aspect minimises the time spent rethermalisating the lattice after
coarsening periods, which we then treat as a new ensemble disjoint from
previous runs. We have tested this technique on the pure gauge 2D Schwinger
model and find that topological sampling rates are improved. We also
demonstrate that autocorrelation times for extensive observables are restored
to their pre-coarsening values after coarsening periods over a acceptably short
simulation time.
