Variational formulation of an age-physiology dependent population dynamics

We transform a deterministic age-physiological factor population dynamics problem into its variational form. The internal/external heterogeneity of a population profoundly affects its dynamics, therefore, apart from age a, a second independent variable, g, say, referred to as the physiological parameter of individuals will also be a basis for classification. Using the well-known Ostrogradski or Gauss formula, we prove the existence and uniqueness theorems for the classical weak solution of the model.