A Coupling Construction for Spin Systems with Infinite Range Interactions

Given a countable set of sites and a collection of flip rates at each site, we give a sufficient condition on the long-range dependencies of the flip rates ensuring the well-definedness of the corresponding spin system. This hypothesis has already been widely used [1-4] but our construction brings a new insight to understand why it is natural. The process is first constructed as a limit of finite spin systems. Then we identify its generator and give a simple criterion for a measure to be invariant with respect to it.