Massive Star Formation

I would be interested in pursuing a project involving the physics of massive star formation. Currently, this area of star formation theory is not well understood. The two main formation models - Competitive Accretion and Core Accretion - both have challenges in describing the process of massive star formation. In competitive accretion, the growth of the massive star is supported by the accretion of ambient gas clumps onto a protostar. It appears to be a slow process which works best in regions of gravitational collapse, and is can be disrupted by stellar feedback. In comparison, core accretion is an extension of the low-mass star formation process, and high-mass stars form from the collapse of molecular clumps of mass M > 8 M. The initial mass function they produce should reflect the core mass function. However, a key question here is what prevents higher mass clumps from further fragmenting as they collapse? I would be excited to investigate these problems further over the course of a PhD.