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.