Stochastic foundation of non-relativistic and relativistic quantum theory, mathematical relativity theory, mathematical physics, applications of differential geometry and global analysis to physics, natural philosophy (in particular the modern foundations of mechanics)
I am a member of BRCP, because I believe the following: Physics, like all sciences, needs people critically engaging with its foundations in order to stay a science. In particular, the idea that quantum physics cannot be understood and that one should not question what is in the books here runs, in my view, directly against the intellectual achievements of the enlightenment era.