article published yes Armand Leclerc author 2a1fb1fc-f373-11ef-901a-87cee43a1217 Guillaume Laibe author Elliot Lynch author Nicolas Perez author LiBu department Unveiling the mysteries of stellar dynamics: a pioneering journey in magnetoasteroseismology project Aims. We investigate signatures of pressure extrema on global oscillations in discs. Methods. We used the framework of wave topology to establish a generalised local dispersion relation that includes pressure gradients. We highlight the influence of a previously unrecognised epicyclic–acoustic frequency, and we derive an analytical criterion for the existence of a branch of modes transiting between the inertial and the pressure bands, known as topological modes. Results. We find that pressure extrema consist of wave guides in which such topological modes propagate. The fundamental mode trapped at a pressure bump can propagate at any frequency, allowing it to resonate with any temporal forcing. Conversely, the fundamental mode associated with a pressure dip propagates at any vertical phase velocity. These specific features make them attractive candidates for future discoseismology. https://research-explorer.ista.ac.at/download/23047/23075/2026_AstronomyAstrophysics_Leclerc.pdf application/pdfno https://creativecommons.org/licenses/by/4.0/ EDP Sciences2026 eng accretionaccretion diskshydrodynamicsinstabilitieswavesprotoplanetary disks 0004-6361 1432-0746 2512.0573710.1051/0004-6361/202558428 708 Leclerc, A., Laibe, G., Lynch, E., &#38; Perez, N. (2026). Radial modes of pressure bumps and dips in astrophysical discs. <i>Astronomy and Astrophysics</i>. EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/202558428">https://doi.org/10.1051/0004-6361/202558428</a> Leclerc, Armand, Guillaume Laibe, Elliot Lynch, and Nicolas Perez. “Radial Modes of Pressure Bumps and Dips in Astrophysical Discs.” <i>Astronomy and Astrophysics</i>. EDP Sciences, 2026. <a href="https://doi.org/10.1051/0004-6361/202558428">https://doi.org/10.1051/0004-6361/202558428</a>. Leclerc A, Laibe G, Lynch E, Perez N. Radial modes of pressure bumps and dips in astrophysical discs. <i>Astronomy and Astrophysics</i>. 2026;708. doi:<a href="https://doi.org/10.1051/0004-6361/202558428">10.1051/0004-6361/202558428</a> A. Leclerc, G. Laibe, E. Lynch, and N. Perez, “Radial modes of pressure bumps and dips in astrophysical discs,” <i>Astronomy and Astrophysics</i>, vol. 708. EDP Sciences, 2026. Leclerc, Armand, et al. “Radial Modes of Pressure Bumps and Dips in Astrophysical Discs.” <i>Astronomy and Astrophysics</i>, vol. 708, A355, EDP Sciences, 2026, doi:<a href="https://doi.org/10.1051/0004-6361/202558428">10.1051/0004-6361/202558428</a>. Leclerc A, Laibe G, Lynch E, Perez N. 2026. Radial modes of pressure bumps and dips in astrophysical discs. Astronomy and Astrophysics. 708, A355. A. Leclerc, G. Laibe, E. Lynch, N. Perez, Astronomy and Astrophysics 708 (2026). 230472026-10-04T22:01:54Z2026-10-07T12:17:34Z