We formulate Positivity Bounds for scattering amplitudes including exchange of massless particles. generalize the standard construction through dispersion relations to include presence a branch cut along real axis in complex plane Maldestam variable $s$. In general, validity these bounds require cancellation divergences forward limit amplitude, proportional $t^{-1}$ and $\log(t)$. show that thi...

We propose a new (chiral) description of partially-massless fields in $4d$, including the graviton, that is similar to pure connection formulation for gravity and massless higher spin fields, latter having clear twistor origin. The approach allows us construct complete examples gravities with (partially-)massless feature Yang--Mills current interactions.