# metadata.dc.description[].value
Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Any: 2014, Tutor: Josep Llosa

# metadata.dc.description.abstract[].value
We discuss systems subject to constraints. We review Dirac's classical formalism of
dealing with such problems and motivate the de nition of objects such as singular and nonsingular
Lagrangian,  rst and second class constraints, and the Dirac bracket. We show how systems with
 rst class constraints can be considered to be systems with gauge freedom. We conclude by studing a classical example of systems with constraints, electromagnetic  eld