MSc defense: Rasmus Strid

Speaker: Rasmus Strid

Title: Different paths to massive higher spin scattering

We review the construction of theories of massive higher spin fields in the canonical formalism as well as the spinor helicity formalism, and discuss the difficulties that arise when interactions with photons and gravitons are considered in these formalisms, in particular the Compton scattering amplitude. We then review an alternative formalism originally introduced by S. Weinberg, which involve $2s+1$ component fields and arbitrary representations, and discuss how this framework may by-pass the difficulties encountered in the previous formalism. In particular, we consider the construction of the off-shell higher spin propagator, which differs from the on-shell propagator found in the literature.