On Microscopic Derivation of a Fractional Stochastic Burgers Equation

We derive, from a class of asymmetric mass-conservative interacting particle systems on Z, with long-range jump rates of order | · |^−(1+α) for 0 < α < 2, different continuum fractional SPDEs. More specifically, we show the equilibrium fluctuations of the hydrodynamics mass density field of zero-range processes, depending on the structure of the asymmetry, and whether the field is translated with process characteristics velocity, are governed in various senses by types of fractional stochastic heat or Burgers equations. The main result: suppose the jump rate is such that its symmetrization is long-range but its (weak) asymmetry is nearest-neighbor. Then, when α < 3/2, the fluctuation field in space-time scale 1/α : 1, translated with process characteristic velocity, irrespective of the strength of the asymmetry, converges to a fractional stochastic heat equation, the limit also for the symmetric process. However, when α ≥ 3/2 and the strength of the weak asymmetry is tuned in scale 1 – 3/2α, the associated limit points satisfy a martingale formulation of a fractional stochastic Burgers equation.