On the number of Regge trajectories for dual amplitudes

A bstract Regge poles connect the analytic structure of scattering amplitudes, analytically continued in angular momentum, to their high-energy limit in momentum space. Dual models are expected to have only Regge poles as singularities in angular momentum space, and string theory suggests there should be an infinite number of them. In this study, we investigate the number of Regge trajectories these models may have. We prove, based solely on crossing symmetry and unitarity, that meromorphic amplitudes, with or without subtractions, cannot produce a reggeizing amplitude if they contain any finite number of Regge trajectories, and show that this excludes the existence of such amplitudes altogether. Additionally, we develop and apply a linear programming dual bootstrap method to exclude these amplitudes directly in momentum space.