Old and New No Go Theorems on Interacting Massless Particles in Flat   Space
  We review model independent arguments showing that massless particles interacting with gravity in a Minkowski background space can have at most spin two. These arguments include a classic theorem due to Weinberg, as well as a more recent extension of the Weinberg-Witten theorem. A puzzle arising from an apparent counterexample to these theorems is examined and resolved. 
M. Porrati
hep-th hep-ph