@article{048fda2c636c4336ae1314731ff8d2bf,
title = "Off-shell Ward identities and gauge symmetries in string theory",
abstract = "I describe a new method of obtaining gauge-symmetry transformation laws for the effective lagrangian of an arbitrary string theory. The method applies to exact as well as spontaneously broken gauge symmetries. The transformation laws, exact to all orders in α' are determined inductively in the number of fields by the corresponding off-shell Ward identities. The case of broken supersymmetry is examined in some detail.",
author = "Massimo Porrati",
note = "Funding Information: Symmetries in string theory, and in particular gauge symmetries, have been given recently a great deal of attention. In ref. \[ 1 \], for example, large classes of four-dimensional strings, both in the bosonic and fer-mionic formulations, were identified as spontaneously broken versions of a few fundamental string models. Even space-time supersymmetric strings can be modified so as to give compactifications that extend the Scherk-Schwarz mechanism of supersym-mctry breaking \[2 \] to string theory. The previous examples point out to the importance of discovering general methods to find gauge symmetries in strings: by their knowledge it may be possible to identify seemingly different string compactifications as generated by the appropriate symmetry breaking of a single string theory. Besides that, gauge Ward identities play an essential role in ensuring the self consistency of the effective low-energy lagrangian. In other words, by identifying each light degree of freedom of spin larger than one half with a gauge vector or spinor, corresponding to a non-anomalous gauge symmetry, one is guaranteed that the effective lagrangian at energies far below the Planck scale is renormaliz-able, and that all effects due to the presence of heavy This work was supported in part by the Director, Office of High Energy and Nuclear Physics, Division of High Energy Physics of the US Department of Energy under Contract DE-AC03-76SF00098 and in part by the National Science Foundation under Research Grant No. PHY85-15857.",
year = "1989",
month = nov,
day = "16",
doi = "10.1016/0370-2693(89)90683-7",
language = "English (US)",
volume = "231",
pages = "403--407",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "4",
}