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Andrew Waldron Brandeis We show that massless and massive propagation is a degeneracy peculiar to Minkowski spacetime. Spin s fields in cosmological backgrounds can be massive (2s+1 DoF) or strictly massless (2 DoF) according to whether the theory is gauge invariant or not. However there are also intermediate theories (2s-1,2s-3,... DoF) thanks to new partial gauge invariances. We also analyze the stability and unitarity of these new models.
Tuesday, May 1st 2001, 13:15 |