asymptotics in astrophysics SG session 4: helioseismology

Constraining the distribution of internal magnetic fields through observations is considered to advance solar dynamo models aimed at understanding the 11-year cycle of solar magnetic activity.
This paper [1] is on the frequency shift of standing acoustic waves inside the Sun caused by internal magnetic fields. Quasi-degenerate perturbation theory is applied to treat perturbation by magnetic fields. I’d like to discuss their methods and application in the session.