Epidemic dynamics and endemic states in mobile agent systems

FERNANDO PERUANI; GUSTAVO J. SIBONA

PHYSICAL REVIEW LETTERS

Año: 2008 vol. 100 p. 1681031 - 1681034

0031-9007

We study the spreading of excitations in 2D systems of self-propelled agents where the excitation is transmitted when a quiescent agent keeps physical contact with an excited one during a non- vanishing time. We show that the steady states strongly depend on the spatial agent dynamics. Moreover, the coupling between exposition time and agent-agent contact rate (CR) becomes crucial to understand the excitation dynamics, which exhibits three regimes with CR: excitation extinction for low CR, an excited regime in which the number of quiescent agents is inversely proportional to CR, and for high CR, a third regime, model dependent, where the number of quiescent agents scales with an exponent z − 1, with z being the scaling exponent of the mean exposition time with CR. This result applied to epidemic spreading suggests that, contrary to what classical epidemiological models state, the epidemic dynamics exhibits more than two regimes with CR.