Asteroseismic Adventures Around Azimuthal Asymmetry

Avoided crossings are an ubiquitous physical phenomenon in the dynamics of few-body systems. I illustrate how they emerge in asteroseismology --- the analysis and interpretation of normal modes in stars --- and specifically in variable stars possessing stochastically-excited oscillations. I describe a one-to-one correspondence between these standing waves and hybridised molecular orbitals. Operational predictions for the frequencies, lifetimes, and visibilities of normal modes emerge from this correspondence, and are now increasingly exploited to yield observational discoveries of stellar rotation, magnetism, and star-planet interactions. Whereas stars are usually assumed to be spherically, or at least azimuthally, symmetric, this approach enables us to relax this constraint in the radial direction. In particular I report recent uses of it to discover a new class of variable stars: those with insides and outsides that rotate around different axes. 

I will conclude with some outlines of ongoing investigations into differentially oblique pulsations under azimuthally asymmetric magnetic configurations.