G. 't Hooft presents a two-dimensional model for mesons, focusing on a gauge theory for strong interactions where planar diagrams dominate. In this model, the gauge field interactions resemble those of a quantized dual string, and the physical mass spectrum exhibits a nearly straight "Regge trajectory." The model is simplified by considering a local gauge group U(N) with N large, allowing for a perturbation expansion in \(1/N\). The Lagrangian includes terms for gauge fields and fermions, with the light cone gauge condition \(A_- = A^+ = 0\) simplifying the dynamics. The model's self-energy parts and ladder diagrams are analyzed, leading to a bootstrap equation for the self-energy. The infrared divergence is handled by a symmetric ultraviolet cutoff, and the resulting dressed propagator shows no physical single quark state. The ladder diagrams satisfy a Bethe-Salpeter equation, and the spectrum of two-particle states is derived. The model predicts a straight "Regge trajectory" for the spectrum, with no continuum corresponding to states with two free quarks. The physical interpretation is discussed, highlighting the absence of transverse motions and the lack of angular momentum. The model's limitations, such as the absence of baryons and the complexity of higher states, are also noted. Computer simulations confirm the qualitative predictions, showing a rapid approach to the straight line trajectory for equal mass quarks and logarithmic spread for higher states.G. 't Hooft presents a two-dimensional model for mesons, focusing on a gauge theory for strong interactions where planar diagrams dominate. In this model, the gauge field interactions resemble those of a quantized dual string, and the physical mass spectrum exhibits a nearly straight "Regge trajectory." The model is simplified by considering a local gauge group U(N) with N large, allowing for a perturbation expansion in \(1/N\). The Lagrangian includes terms for gauge fields and fermions, with the light cone gauge condition \(A_- = A^+ = 0\) simplifying the dynamics. The model's self-energy parts and ladder diagrams are analyzed, leading to a bootstrap equation for the self-energy. The infrared divergence is handled by a symmetric ultraviolet cutoff, and the resulting dressed propagator shows no physical single quark state. The ladder diagrams satisfy a Bethe-Salpeter equation, and the spectrum of two-particle states is derived. The model predicts a straight "Regge trajectory" for the spectrum, with no continuum corresponding to states with two free quarks. The physical interpretation is discussed, highlighting the absence of transverse motions and the lack of angular momentum. The model's limitations, such as the absence of baryons and the complexity of higher states, are also noted. Computer simulations confirm the qualitative predictions, showing a rapid approach to the straight line trajectory for equal mass quarks and logarithmic spread for higher states.