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arXiv · hep-th/0405119

Loop Variables and Gauge Invariance in Closed Bosonic String Theory

B. Sathiapalan
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Abstract

We extend an earlier proposal for a gauge invariant description of off-shell open strings (at tree level), using loop variables, to off-shell closed strings (at tree level). The basic idea is to describe the closed string amplitudes as a product of two open string amplitudes (using the technique of kawai, Lewellen and Tye). The loop variable techniques that were used earlier for open strings can be applied here {\it mutatis mutandis}. It is a proposal for a theory whose on-shell amplitudes coincide with those of the closed bosonic string in 26 dimensions. It is also gauge invariant off-shell. As was the case with the open string, the interacting closed string looks like a free closed string thickened to a band.

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B. Sathiapalan. 2004-05-13. Loop Variables and Gauge Invariance in Closed Bosonic String Theory. https://doi.org/10.1142/s0217732304015713

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