Local structure of current fluctuations in diffusive systems beyond one dimension

In order to illuminate the properties of current fluctuations in more than one dimension, we use a lattice-based Markov process driven into a nonequilibrium steady state. Specifically, we perform a detailed study of the particle current fluctuations in a two-dimensional zero-range process with open boundary conditions and probe the influence of the underlying geometry by comparing results from a square and a triangular lattice. Moreover, we examine the structure of local currents corresponding to a given global current fluctuation and comment on the role of spatial inhomogeneities for the discrepancies observed in testing some recent fluctuation symmetries.