The instability of travelling waves (TW) in high-order operators has been a source of investigation in the last years. Instability shall be understood as the existence of oscillatory exponential bundles of solutions. One of the principal topics to explore is related with the characterization of the mentioned instability phenomena in the proximity of the stationary solutions given by KPP-Fisher terms. Along this analysis, the main areas discussed cover TW instability, TW propagation speed and characterization of a local inner region with positive monotone behaviour of solutions (also called positive inner region). Furthermore, a sharp estimation of the TW propagation speed to ensure the existence of such positive inner region is obtained. Eventually, insights on regularity, existence and uniqueness of solutions are provided as supplementary information.

高阶算子中行波 (TW) 的不稳定性一直是过去几年研究的一个来源。不稳定性应理解为存在振荡指数丛的解。要探索的主要主题之一与 KPP-Fisher 项给出的平稳解附近的上述不稳定现象的表征有关。在此分析中，讨论的主要领域包括 TW 不稳定性、TW 传播速度和具有正单调解行为的局部内部区域（也称为正内部区域）的特征。此外，获得了对 TW 传播速度的精确估计，以确保这种正内部区域的存在。最终，洞察规律性，