Urríes, F. J. deJulve, J.Sánchez, E. J.2016-09-092016-09-092001De Urries, F. J., Julve, J., & Sánchez, E.J. (2001). Higher-derivative boson field theories and constrained second-order theories. Journal of Physics A: Mathematical and General, 34(42), 8919-8940. DOI: 10.1088/0305-4470/34/42/31403054470http://hdl.handle.net/11268/5732As an alternative to the covariant Ostrogradski method, we show that higher-derivative (HD) relativistic Lagrangian field theories can be reduced to second differential order by writing them directly as covariant two-derivative theories involving Lagrange multipliers and new fields. Despite the intrinsic non-covariance of the Dirac procedure used to deal with the constraints, the explicit Lorentz invariance is recovered at the end. We develop this new setting on the basis of a simple scalar model and then its applications to generalized electrodynamics and HD gravity are worked out. For a wide class of field theories this method is better suited than Ostrogradski's for a generalization to 2n-derivative theories.engjournal article10.1088/0305-4470/34/42/314restricted accessFísicaMatemáticasCiencias físicasMatemáticas