Saturday, 26 March, 2022

Subdiffusive Activity Spreading in the Diffusive Epidemic Process

B. Polovnikov, P. Wilke, E. Frey

10.1103/PhysRevLett.128.078302

The diffusive epidemic process is a paradigmatic example of an absorbing state phase transition in which healthy and infected individuals spread with different diffusion constants. Using stochastic activity spreading simulations in combination with finite-size scaling analyses we reveal two qualitatively different processes that characterize the critical dynamics: subdiffusive propagation of infection clusters and diffusive fluctuations in the healthy population. This suggests the presence of a strong coupling regime and sheds new light on a long-standing debate about the theoretical classification of the system.