Lagrange brackets and U(1) fields

The idea of a companion Lagrangian associated with p-branes is extended to include the presence of U(1) fields. The brane Lagrangians are constructed with F-ij represented in terms of Lagrange brackets, which make manifest th e reparametrisation invariance of the theory; these are replaced by Poisson brackets in the companion Lagrangian, which is now covariant under field r edefinition. The ensuing Lagrangians possess a similar formal structure to those in the absence of an anti-symmetric field tensor. (C) 2000 Elsevier S cience B.V. All rights reserved.