Removal of instabilities of the higher derivative theories in the light of antilinearity

Abstract Theories with higher derivatives involve linear instabilities in the Hamiltonian commonly known as Ostrogradski ghosts and can be viewed a very serious problem during quantization. To cure this , we have considered properties of antilinearity that found inherently non-Hermitian Hamiltonians. Owing to existence antilinearity, construct an operator, called V -operator, which acts intertwining operator between its Hermitian conjugate. We used -operator remove momentum term from derivative by making it first place via isospectral similarity transformation. The final form is free under some restriction on mass term.