“…Elliptic-hyperbolic equations emerge in a diverse range of real-world physical phenomena. Examples include the dynamics of plasmas under the influence of small-amplitude electro-magnetic waves with phase velocities significantly greater than thermal velocities [26,45,47,49], the behavior of light near a caustic [43], extremal surfaces in the context of special relativity, the formation of rapids, transonic and multi-phase fluid flow [17,22,36], the dynamics of certain models for elastic structures [51], the shaping of industrial surfaces like windshields and airfoils [9], issues related to traffic flow [4], and harmonic fields in extended projective space [48]. Additionally, these equations find applications in models connected with the early Universe [30], cosmic acceleration, and the possible violation of causality within the interiors of specific compact stars.…”