Authors: Junwei Zhao (Stanford Univ), Tongjiang Wang (Catholic Univ of America), Ruizhu Chen (Stanford Univ)

Quasiperiodic propagating perturbations observed in coronal fan loops are commonly interpreted as slow magnetoacoustic waves. While extensively studied, the question of whether these waves exhibit dispersive behavior has remained largely unexplored. In this study, we estimate the phase speeds of the waves as a function of frequency by computing cross-correlation functions in the Fourier domain. Our results reveal a clear trend: phase speed generally increases with frequency over the range of 4–15 mHz, providing strong observational evidence that these waves are indeed dispersive. We also conducted a few data experiments to validate our analysis method, confirming the robustness and reliability of our findings.