Massive-Star Magnetospheres: The Interplay between Outflows, Rotation and Magnetic Fields

Over the past decade, the rapid progress in the detection and characterization of magnetic fields in massive stars has been 
matched by a corresponding expansion in our understanding of the glowing, circumstellar magnetospheres which these fields 
sculpt. The topology and distribution of gas trapped in a massive-star magnetosphere depends on the delicate interplay 
between the radiative forces responsible for the star's wind outflow, the inertial forces arising from rotation, and the magnetic 
forces exerted by the field itself. In this presentation, I will summarize the various conceptual paradigms that have been 
developed to understand and explore this interplay, focusing in particular on simple limiting cases which can be used 
to illuminate more-complex scenarios. I will then highlight shortcomings of current models, in particular those indicated by 
observational techniques which incorporate some kind of spatial resolution --- e.g., Doppler tomography, linear polarization, 
and perhaps one day interferometry.