Abstract Stability and causality are studied for linear perturbations about equilibrium in Carter’s multifluid theory. Our stability analysis is grounded on the requirement that entropy of multifluid, plus environment, must be maximised at equilibrium. This allows us to compute a quadratic Lyapunov functional, whose positive definiteness implies stability. Furthermore, we verify explicitly that...

The construction of general derivative self-interactions for a massive Proca field relies on the well-known condition constrained systems having degenerate Hessian. nature existing constraints algebra will distinguish among different classes interactions. Proca-Nuevo interactions enjoy nontrivial constraint by mixing terms various order whereas generalized satisfy degeneracy each individual Lag...