Comment on 'A note on first-order formalism and odd-derivative actions' by S Deser

We argue that the obstacles to having a first-order formalism for odd-derivative actions presented in a pedagogical note by Deser (Class. Quantum Grav. 23 5773) are based on examples which are not first-order forms of the original actions. The general derivation of an equivalent first-order form of the original second-order action is illustrated using the example of topologically massive electrodynamics (TME). The correct first-order formulations of the TME model keep intact the gauge invariance presented in its second-order form demonstrating that the gauge invariance present in the original action is not lost when one correctly employs the Ostrogradsky procedure. (comments, replies and notes)