Unitarization Schemes for High-Energy Elastic Scattering

We examine key features of the eikonal and $U$-matrix unitarization schemes and apply both frameworks to investigate the high-energy behavior of the elastic scattering amplitude, considering input amplitudes whose asymptotic behavior is driven exclusively by Pomeron exchange. Particular attention is devoted to assessing how the extracted Pomeron parameters depend on the assumed trajectory form. In this context, we compare linear and nonlinear Pomeron trajectories, evaluating their impact on the phenomenological description of the data and on the stability of the fitted parameters.