Removal of arbitrariness in the two-time correlator solution

Develop a solution method for the two-time voter-model autocorrelator on fractal substrates that avoids the apparent arbitrariness arising from the singular Mellin-transformed system with infinitely many solutions.

Background

To obtain the two-time autocorrelator, the paper reduces the problem to a singular two-by-two system after applying a Mellin transformation. Because the system has infinitely many solutions, the authors select one by imposing a physically motivated condition, such as continuity in the Euclidean limit. They explicitly ask whether the solution technique can be improved so that this arbitrary choice is avoided.