The non-standard Lagrangian from non-uniqueness principle of the real scalar field and fermion field

We construct the non-standard Lagrangian, called the multiplicative form, of the homogeneous scalar field and fermion field through the inverse calculus of variations, which the equation of motion still satisfies the Klein-Gordon and Dirac equations, respectively. By employing the non-uniqueness of Lagrangian, we show that the Lagrangians can be written between the linear combination of standard and non-standard Lagrangian. The stability of the ghost field, an unnatural smallness of cosmological constant, and the chiral condensate are discussed by applying these new Lagrangians.