Five ways to model active processes in elastic solids: active forces, active stresses, active strains, active fibers, and active metrics

An important contribution of Gerard Maugin was his study of anelasticity. It is well appreciated that in biological systems, anelasticity manifests itself through growth and remodeling and Maugin and his collaborators have helped build a general theory suitable to model such fundamental processes. Yet another important manifestation of anelasticity is the active processes found in all living systems.